Is that really true, though? I can't think of any significant examples of games from the '80s or '90s that involved "in-groups punching... on out-groups", unless the out-groups in question were space aliens, nazis, fantasy monsters, hostile AIs, or the like.

Monkey Island is an absolute classic, of course, but this particular point feels almost like a retcon of present-day cultural assumptions into a specific context in the past where the objects of this criticism weren't really quite so present.