Why are there so many styles or systems of karate?

Simply, a personal signature on the one single form of Ti or Toudi that is Okinawa Ti. Ti is the term used to designate and denote a singular form of empty handed defense that today is referred to as karate, i.e. formally China-hand and currently empty-hand. The various styles and systems such as Isshinryu, Gojuryu, and Shorinryu, etc. are those designations given by individuals who have reached a level of mastery in Ti/Toudi that they feel the need to name their own personally formed system that is ti/toudi but with a personal signature or essence that makes the distinction that this person is responsible for this way of practicing, training and using Ti/Toudi. 

In a nutshell, my view, is this is merely a form of ego driven recognition and in modern times a means by which one differentiates a teacher and style from others with promotions as to a particular personality of the person and style as unique thereby bringing more students and income into the dojo. Cynical, yea a bit but with a smidgeon of truth. 

Lets look at this a bit historically. At first there was only Ti/Toudi. Then to distinguish it was to separate it from one another as to location ergo why Ti took on names such as Tomari-ti, Shuri-ti and Naha-ti. To distinguish is actually a need for man to differentiate and make unique something that was previously shared by all. 

As time passed and as it became more available to all Okinawans there came a further need to differentiate, distinguish and make unique the jutsu of ti into systems/styles that were associated with individual masters of long standing especially since the three main villages slowly were absorbed into many that is Okinawa, i.e. Goju-Ryu, Shorin-Ryu, Uechi-Ryu, Isshin-Ryu, and so on. 

Even today in modern times those original "styles" soon branched off into more unique styles and systems associated with new and more prolific masters to differentiate between just karate and the special karate's that you would need to fight and defend or worse compete. There are not a long list of variations within a system like Shorin-ryu, i.e. 

Shōrin-ryū Reihokan[8]

Shōrin-ryū Shidōkan normally called Shidōkan or Okinawan Shidōkan

Shorinkan

Kobayashi Shorin-ryu

Shōrin-ryū Seibukan

Okinawa Seidokan Shōrin-ryū normally called Seidokan

Shōrin-ryū Kyudōkan normally called Kyudōkan

Koporyu Shorin-ryu

Oshukai[9]

Okinawa Shorin-ryu karate Shinkokai

Chubu Shorin-ryu[10]

Matsubayashi-ryu (also translates to Shorin-ryu)[10]

Shorin-ryu (Shaolin)[10] also known as Shobayashi.

Ryukyu Shorin-Ryu[10]

Rendokan Shorin-ryu

Seibukan Shorin-ryu

Matsumura Seito Shorin-ryu

Even in the singular style/system of Isshinryu there are many different factions of that system yet to be renamed into new more individualize unique systems/styles except those who merely added to the name Isshinryu, i.e. Advincula's Isshinryu, Long and Wheeler's Isshinryu, and Nagle's Isshinryu - all three practiced and taught differently with small variations, etc. 

In the end there is absolutely nothing wrong with this as long as the practitioner/participant knows this and understands that in reality there is only one system of karate called "Ti" and that all of them are fundamentally the same except for that unique signature on Ti used by the dojo sensei for teaching, and often renumeration sake, today's karate of Okinawa. In the end all systems and styles of martial systems rely on the same exact fundamentals, the fundamental principles of martial jutsu or in this particular case, "Ti."

Addendum dtd Friday February 21, 2014 at 15:15

It is also stated in an article written by an Okinawan karate master that his belief is that styles were adopted by Okinawans due to the historical influences of Japan's martial systems that rely heavily on a hierarchal system, etc. Because Okinawa was absorbed by Japan and Japan dictated this along with influences through the interactions of Okinawan masters and Japanese martial arts, i.e. Funakoshi Sensei, etc. this came into being, i.e. styles and systems. 

Ti is Ti or Toudi. The principles of martial systems are the concrete foundation of all variations of empty handed Asian combatives. Putting a unique stamp on a personal version is just that, a symbol or stamp or title to differentiate a personal belief and view of a singular system of Okinawan Toudi.

How do I know if I am practicing a Martial Art?

First, you have to understand what a martial art is and that is not so clear. Second, martial arts actually includes all systems of combatives/fighting and this includes our systems here in the America's as those in Europe, etc. A martial art is a system with traditions and associated cultures and beliefs of combat practices. 

Third, you have to differentiate between what is considered classical/traditional martial arts and then those that are more modern. In my perceptions very few of what we term as martial arts is truly a martial art. But then again the "art" part does differentiate those that are born of the jutsu. Jutsu referring to the technique, method and skill used to fight, combatives. 

Does this include self-defense? Yes and no, because self-defense is always a part of combatives and combatives are about offense and defense with a stronger emphasis on offense, i.e. where in combat you are trying very hard to make the enemy die for his beliefs while you live to promote yours by combat. Self-defense is further muddled by the restrictions, i.e. the laws, etc., imposed by society that is increasingly disconnected from what is violence and what is perceived violence along with what is necessary to survive violence. 

I guess the reality is that martial arts of old now encompasses those activities that are more toward a symbolic venue geared to satisfy the need to be proficient in combatives while not actually causing damage and death. I guess it is now a matter of degrees. Yet, I feel strongly that martial arts are either bu-jutsu oriented or sport oriented with symbolism toward bu-jutsu or sport oriented with emphasis on competition and winning trophies, accolades and egoistic pride building. 

If I were to follow my perceptions and beliefs as to martial arts then most of what I have seen and experienced in modern marital arts in not truly martial arts. It is a bit like the label "karate." Karate is often used to label many systems that are not karate. Where does all this misconception come from, from media events such as television and movies where reality is often sacrificed for drama. Even those industries are misled by today's view within the martial arts world. We are so blinded by what is perceived as to looks we tend to think things that look good and impress observers is what works in combatives. Here again lies the crux of this issue, what is violence and how does violence manifest itself in all its forms - and there are many forms to know about.

So, how do you know if you are practicing a martial art? Well I guess in the end it is how you perceive things, what you believe in and what makes you feel comfortable (note: if you are comfortable with your martial art you have to ask why you feel the comfort because violence and classical martial arts involves a lot of discomfort - an enjoyable, sorta, discomfort.). 

This is one of those questions you will have to consider, analyze and change as you grow in depth and breadth of practice and training. It is one of those things that is personal and causes a lot of discourse as to personal views and beliefs. If you cannot look at yourself, your practice and your system with an open mind, if you find you resist vehemently then maybe your stuck in a false belief - usually a sign when you resist in the face of truth, facts and reality. 

Then again if you are comfortable, having fun and have a solid social connection with your dojo mates then it matters not - except if you encounter violence and it fails to work for you. When one thinks martial art they assume it is a means of self-defense when it may not be exactly what you assume or expect. Even those who truly practice a martial art may find things not working as intended. 

Convoluted and Complex Topic!