Well how can you say that if you take the FEAST by practicing, it's useless, because you might ( most likely ) fail the training ?
The ATC job is %1 of what this exam tests. I might have other skills and learn very fast. A test can never tell ME that I am not good enough for something. Until you haven't tried and see live what happens, you can't say I don't fit there.
Don't underestimate the human will and the brain.
And again, I'm saying all of these, because I have a relative that is an ATC for 15 years and she went to her exam with thoughts like "meh, lets give it a try, can't kill me", yet she's very good now and compared to me at her age back then, she's not as smart and intelligent as I am. So who says I can't learn in a very short time everything and be successful at this job?
Also, you can take FEAST first try, without any practice, that doesn't mean you are going to be a good ATC even if you pass all the training.
Everything is relative.