It's a very unpopular opinion because the precedent set (compulsory ID verification for online stuff) is very much not worth the thing that you think you're get

It's a very unpopular opinion because the precedent set (compulsory ID verification for online stuff) is very much not worth the thing that you think you're getting (improved behavior in an online social network). Assume that tomorrow you started requiring compulsory ID verification for, say, entering public parks. It's possible that this would lead to some improvement in the general conditions of public parks. But you would still think of it as dystopian bullshit. This is the same.