I mean there are a million situations that would call for a specific, non-individual bedtime for practical reasons, and having someone informed to make that call and help everyone actually get well rested for the morning's action is useful.

But its only used as a knee jerk reaction because it infantilizes our anarchist comrades so... That sucks

When people mention it, they aren't trying to convey the need for imposed bedtimes except on children, which so the meme goes some people consider an injustice. As I understand it, it's about a knee jerk opposition to any situation where one person tells another what to do. But like I said in the comment, I don't think it's that helpful here (nor is it in most other contexts).