"Miners can just put malicious stuff in blocks, so disallow nodes from having any say over whether or not they can reject that stuff from their mempools."

Wakey wakey everyone.

The heart of the issue with Bitcoin Core is this: They are seeking to disallow Bitcoiners any means by which they can decide what does/doesn't end up in their mempools.

This is a critical and almost-never discussed aspect of what makes Bitcoiners sovereign.

You are not running a free service for miners where you must seek and relay to them whatever pays them the most.

Your node is yours to do with what you deem appropriate.