Because the problem of bad faith attacks can only get worse if you fold every time.

Sooner or later society has to come emotionally to terms with the fact that other times and places value things completely different from us, hold as important things we don't care about and are indifferent to things we do care about.

Intellectually I'm sure we already know, but e.g. banning old books because they have reprehensible values (or even just use nasty words) - or indeed, refusing to release a model trained on historic texts "because it could be abused" is a sign that emotionally we haven't.

It's not that it's a small deal, or should be expected to be easy. It's basically what Popper called "the strain of civilization" and posited as explanation for the totalitarianism which was rising in his time. But our values can't be so brittle that we can't even talk or think about other value systems.