I think many martial arts can be trained "more effectively." For example, I am currently training mainly in Jeet Kune Do. However, I used to be an assistant instructor in my Tae Kwon Do class at the University of Rochester. My instructor mainly concentrated on the traditional stuff such as forms, basics, three-step sparring drills, and freesparring drills. From my background in FMA and training with others, I included the "attitude"--not just drills, I developed into my classes.
For example, I had them include more movement in their pad work (and also increased the amount of padwork they did). Also, I noticed many students did not punch with "intent" for their opponent's to defend--not on target, lazy, or "too" slow. I tried to help them develop habits for their training within the system as well as giving them some supplementary training--for example, with some boxing drills and combinations and techniques.
However, I think after a certain level in TKD (from my own experience) I needed to look elsewhere. I felt my TKD school concentrated too much on traditional forms without application and I found my interests were too different than I wanted or perhaps needed. I had trained in FMA and rekindled some of my old instructor-student relationships as well as finding my current instructor in JKD.
I think one needs to look at what they want out of their martial arts. If they want more combative training, they must seek the instructors or classes that provide it. If they want sport, then they should find the schools that concentrate in that.
I am still good friends with many of my TKD friends and sometimes go an instruct for fun and to give them a different flavor, but my training has changed alot for the better (for me).
NB I'm not trying to bust on TKD or any other art, but I think one needs to see whether their school satisfies their needs. I don't think it's a matter of ITF or WTF even but a lot must look at their own school individually.
Cheers,
Bryan