I addressed exactly this. This is what you are doing:

> The second Facebook censors anything, they are immediately hit with a furor of complaint that, under those standards, they are obligated to censor some slightly less objectionable thing.

This is like trench warfare. Facebook never drew an arbitrary line: it just kept being pushed back by public and media pressure here and there, retreating in bits and pieces. Obviously if you just ignore that history, it looks like an arbitrary line now, but it was created by complaints almost identical to the ones you're making.