People are using the major compound lifts because of elite athletes and pro body builders, if you go into the ideal physique thread it's nothing but athletes being posted, so me bringing up Gymnasts and Boxers is no different, people are using athletes/body builders as their targets.
The target is simply to look better for the vast majority of people lifting, and truthfully speaking if they knew better, starting out the majority would be doing isolation work instead of the compound lifts. That video above by Elliot is from the perspective of someone that competes in Strongman competitions, stabilizers for him are paramount to success....they aren't necessary for the dude that wants to look better at the beach and works in an office. And if stabilizers were really key, nobody would touch the barbell bench over the DB bench, even though it's one of the compound lifts.