Here's the thing: I agree with you on .world, but last I knew, .ml was STRUGGLING to not be seen as 'the default catch-all'. I don't believe ALL OF THEM belong on the flamethrower-ing list. I mean sure, the third of .ml that is loudly and obnoxiously anti-marxist can get on that list, but surely not the whole instance.
it seems important to me to advocate that we don't completely alienate new users. Lemmy.ml may be the second largest most diverse instance behind .world but I vividly remember when migrating over that I wanted to sign up with at least one instance that maintained populated discussions on more than one current event. Lemmy is still pretty niche on its own, generally speaking.