The issue here is that I, as a gamer, want to know if developers espouse opinions that I strongly disagree with, because I don't want to give them my money. So if a developer was (for example) in the Epstein Files, I would want to know that before buying their game. Reviews are an effective way to communicate that information, and I'd be rather upset to see them go.

You can't reasonably allow reviews outlining some developer behavior and disallow others - that's straight up censorship. As much as I disagree with the 'I will downvote games by someone who celebrated Charlie Kirk's death" stance, I think it's their right to take that stance. I'm not really sure how you reconcile those two things without just banning them both.

What Steam could do is have a separate review category (from 'normal' ones and 'off-topic' ones) to categorize character profiles of the developers, and let people opt in or opt out of having those included in the aggregate score. Alternately, they could categorize reviews by the reason (e.g. "Performance / crashes", "Unfun", "Too hard", "Too Woke", "Developer is a horrible person"), and let people choose which categories they care about.