Just an observation, based on 20 years in BBS and web forums:

The majority of people do get emotionally involved in forum debates, to some extent. Just because they don’t know someone or can’t see them doesn’t mean that person’s words can’t have an effect, for good or ill. Most are decent, but plenty of nasty people fall into this category.

There are a few who do not get emotionally involved at all. These are generally only a**holes by accident, because by definition they aren’t evil, only socially inept.

There are more than a few who do get emotionally involved, pretend not to, and enjoy making and watching others squirm. These are the worst, and most deserving of the bad karma they’re racking up. If you believe in that kind of thing.