I don't know why people don't think that the shortcomings of TaeKwonDo can't be modified? The discussion is if the flaws I outlined are inherent or not. I personally find it difficult to make TKD work without turning it into an American Kickboxing-like system, but I think an argument could be made, surely.
The fundamental flaw in your viewpoint is the constant conflation of martial art and sport.
An example: the wtf taekwondo I did is not how you use those same taekwondo lessons in a pub. That Olympic style competition is a game that is shaped by the rules. For a Thai boxer to become a good tkd fighter he would have to adapt to be the most efficient he could be within the rules.
Conversely the same is true for a tkd fighter going into muay Thai rules fighting. Neither thing is a fighting style, they are games played differently to one another.
So by comparing them you are saying what if I take my drag racer and put it in a formula 1 race.
The comparison is pointless and says nothing about the art, only the ruleset under which the competitor trains.
That is not to say you can't use combat sports skills or methods in real fighting, but its not the environment that the fighters train for.
Essentially everything is crap except mma, and then only the one's with nearly no rules. That is as close to martial art as you can get.
And yes I acknowledge that traditional training doesn't usually come close to preparing people for that level of fighting, but again:
Training is not martial arts. Training is training.