There's even a well known shorthand for the subset of feminists that carve out exceptions for sex workers: SWERF. Sex Worker Exclusionary Radical Feminist.

This is not a new issue.

However GP didn't say "all feminists", only "feminists".

If I say "Germans eat bread for breakfast" that's generally understood to mean "In general Germans eat bread for breakfast" or "A majority of Germans eat bread for breakfast". Treating it as if I said "Every German eats bread for every breakfast" would be constructing a straw man. People generally understand that there is variation in every group, even if they don't explicitly put that disclaimer on every sentence.

It is not exactly comparable. Prostitution is an important issue in feminism. Statement "environmentalists support nuclear power" would be a better analogy, because many environmentalists are for nuclear power and many are against.

I'm not convinced the comment I replied to is a valid generalization capturing what the majority of feminists believe.

I thought we’d decided “not all X” arguments were inadmissible?

not all Hacker News posters are full of shit? Help out, I'm kinda lost now.

This is untrue rather than inadmissible.