No it would be stupid to think that, however if there is an argument between two ideologies, the side that gives the most Freedom should be the side that’s represented I would have thought the fediverse of all places would agree with that principle.
Secondly that option already exists on at least the three instances I’ve signed up. I figured it was a universal setting, Whether that option actually works or not I’m not sure because I’ve never actually checked it because I don’t mind Bots if there’s one that’s annoying I just block it.
As for your last part, I wouldn’t agree that Bots are a cheap way to drive engagement, most Developers won’t make a bot with the expectation of bringing more users to the platform or drive engagement, they make a bot to fill a gap in utility that the platform is not currently giving, Beit entertainment, moderation, informational. The only platform that I can think actively creates Bots with the intention of increasing monetary value and engagement would be Discord and even then that’s more of a stretch because it’s more Discord forcing the monetary features on the Developers