Greetings..
I believe the question was put to me of "What background do you have for evaluating those techniques and evaluating their worth? "... Only my own experience, the same experience that has taught me not to assume the words of others are less than valid without some evidence to the contrary...
Suppose you go fishing and the local "fishmaster" says to use a certain lure.. 2 hours later and no fish, you try another lure and you begin to catch fish.. work with me here, do you chastise yourself for abandoning the local wisdom, or go home with lots of fish.. Same as in the rest of life, if it doesnt work for you and something else does, common sense suggests that we go with the obvious.. poor teacher? poor student? the only thing that matters is, does your training serve you when it's needed? not like the guy sitting in the parking-lot holding a handfull of his teeth mumbling something about the victor's poor technique.. I would rather win with what works for me than lose because i couldn't escape the dogma..
Training is just that, "training".. training for the real thing, not the ring, not for show, just that one "speeecial" moment when it actually matters... and, that's the only experience that matters.. I've seen too many "show-dogs" take one good hit and fold, don't mistake training or styles for the real thing, it's not.. when it's actually "on", you find out what "works", and you may be surprised...
As for JKD, i think of it less as a style and more as a philosophy.. but, the philosophy dictates that we train hard and with focus on what has worked before, while keeping an open mind to deal with the developing new styles (ie: MMA) and such... if you're arguing about the purity of JKD as a style, you really have missed the point..
Be well...