Flying Crane
Sr. Grandmaster
I think that most arts have a whole lot of depth to them that most people never come close to tapping into. Unfortunately that gets more and more difficult as time goes on because there are fewer and fewer people who do have that deep understanding, and a whole lot of the "teachers" out there do not. If the teachers never got to the depth, they can never bring their own students to the depth, and it gets lost forever eventually. But some still have it, they are just rare and hard to come by.
For people who do not have access to such a teacher, it's not their fault. That's just life, and life ain't fair. So people do the best they have with what they have to work with. The problem is, in most cases they do not even realize what is missing from their training. They may have learned all the formalized curriculum of their system, but their depth of understanding is shallow. So all they understand is: "I've learned the entire system, so I've got it." They may have learned the entire system, but they still don't get it.
In my opinion, most people are looking at their training on a technique level, and few really get to understand their system on a principle level. Technique is very important, and one can be quite skilled and successful on that level. But if you really get to understand the system on a principle level, then you grasp what really makes everything work the best, and you can also understand what might not be compatible to adopt into a system. If your level of understaning is on the technique level, then I suspect the goal becomes chasing after all the techniques that one might need in their arsenal, in an attempt to fill in any "holes" that their system may have. But if you really understand the principles, then you understand how to make your method work against anybody, no matter what method your enemy may attempt to employ against you, and you realize that you do not need to collect all the techniques that exist. A strong grasp of the principles gives you a better and stronger ability to adapt to a situation spontaneously, and create an appropriate technique to fit the situation, rather than plumbing the lists of techniques that have been collected. The latter can also work, but it's my opinion that the former gives you the tools to make it work better, and with less clutter as an approach to training.
What I see happening in most of the "Frankenstein" cobbled-together martial arts, is someone who is chasing after techniques because he never really grasped the principles. He sees "holes" in his list of techniques and he is trying to fill those holes. But if he really understood his system on the principle level, he would realize that those holes don't actually exist, and his system gives him the means to deal with any situation. He doesn't need to chase after techniques and lengthen his lists.
For people who do not have access to such a teacher, it's not their fault. That's just life, and life ain't fair. So people do the best they have with what they have to work with. The problem is, in most cases they do not even realize what is missing from their training. They may have learned all the formalized curriculum of their system, but their depth of understanding is shallow. So all they understand is: "I've learned the entire system, so I've got it." They may have learned the entire system, but they still don't get it.
In my opinion, most people are looking at their training on a technique level, and few really get to understand their system on a principle level. Technique is very important, and one can be quite skilled and successful on that level. But if you really get to understand the system on a principle level, then you grasp what really makes everything work the best, and you can also understand what might not be compatible to adopt into a system. If your level of understaning is on the technique level, then I suspect the goal becomes chasing after all the techniques that one might need in their arsenal, in an attempt to fill in any "holes" that their system may have. But if you really understand the principles, then you understand how to make your method work against anybody, no matter what method your enemy may attempt to employ against you, and you realize that you do not need to collect all the techniques that exist. A strong grasp of the principles gives you a better and stronger ability to adapt to a situation spontaneously, and create an appropriate technique to fit the situation, rather than plumbing the lists of techniques that have been collected. The latter can also work, but it's my opinion that the former gives you the tools to make it work better, and with less clutter as an approach to training.
What I see happening in most of the "Frankenstein" cobbled-together martial arts, is someone who is chasing after techniques because he never really grasped the principles. He sees "holes" in his list of techniques and he is trying to fill those holes. But if he really understood his system on the principle level, he would realize that those holes don't actually exist, and his system gives him the means to deal with any situation. He doesn't need to chase after techniques and lengthen his lists.
At some point, a talented person attracts the attention of others who wish to understand the skill they have witnessed, and a new school is born out of their experiences, which often include training in at least a couple different areas. Some schools thrive and grow and adapt, and some schools last only a generation or two and die out. Not every mutation is beneficial, and even those that are useful do not always remain so as changes in environment may make a once useful mutation into a hindrance and then it will die out. The styles we have today are the few lucky ones which survived, and they continue to adapt and change, and will mate together and produce offspring that none of us can predict 
