Ok, I'll add my suggestion after mulling your statement for a couple of seconds....That is what I believe from empirical evidence, yes. Profitable traders are almost as rare a breed as true psychopaths, and forensic experts, you can train idiots all their life to solve complex murder cases, 1 in 1000 has the right mental makeup to excel in that niche job. All others fail regardless how much education you throw at them. There are very few jobs on this planet that require unlearnable traits and talents. I believe profitable trading is one of them. Another is being a profitable poker player. Very very rare breeds.
You may be right for traders who trade succesfully day in day out, eg short term traders pulling trigger several times a day (sort of) but for longer term traders such as myself, I average around hold time of 2 months, maybe doesn't apply. Much easier imo to be profitable on longer time frames. A prop shop would sack me as my activity is too low, 180 positions placed in 1-1/2 years (since keeping a log record).