Firstly, loads of these aren't fully evolved, so that's a factor. You'd usually want the highest stats possible, and on lower stage evolutions most of the time you use the Eviolite as an item, which means you can't passively heal away the Substitute cost of 25%.
Secondly, stat wise, it's just unviable for many of them. Yes Mega Alakazam can learn it, but you may as well hit your opponent with his multitude of spoons instead, it'd do more damage. You also have to consider getting the Substitute up as well, either a threatening Pokemon to set up on the switch (such as Mega Mawile) or a bulky one like Conkeldurr.
Finally, is it worth it? To pull off such a set, you have to dedicate 2 moveslots to a 150BP Fighting attack, whilst sacrificing 25% of your HP and the possibility of simply not being able to set up. In most cases, the Fighting type STAB users have moves that are much better for them, such as Drain Punch to recover Conkeldurr's health or Close Combat on Infernape to quickly KO the opponent. For those that use it as coverage, again they usually have access to more viable Fighting type moves that are more beneficial, or they sometimes don't need the coverage, such as Charizard.
TL;DR
- Can it sustain the 25% cost? (Healing moves, Leftovers etc.)
- Does it have the Attack to actually make it worth using?
- Can it actually set up? (Threatening/bulky?)
- Does it have better options?
- Is it worth sacrificing 2 moves for a set up which may not work?
