I tend to stick to political and non-personal debate threads, as the millions of repetitive posts when people haven’t read the thread are boring, and I don’t see the point in posting if nobody is reading. I enjoy a debate in ‘real life’ too, but the difference online is that you can refer people back to what you actually said if they have jumped to conclusions. I do find that that happens a lot on here - you say one thing, and some posters read another, and make huge assumptions to fit their own world view. The ‘one person’s passionate supporter is someone else’s bigot’ thing is more of a truism on here than in real life.
I am probably more direct on here, as ‘in real life’ I am more likely to know the circumstances of people I’m talking to, and can therefore be more tactful. Online you can only respond to what people say, and can’t put it into context unless they have disclosed enough about their lives (and you have remembered). Also, I don’t see pointing out inaccuracies or illogical jumps in arguments as being personal comments - I think this has to be done when people keep using them to twist what others have said, or to divert the conversation away from something that disproves their point of view. In my opinion ‘You are stupid and can’t string a sentence together’ would be a (very) rude and personal comment, but ‘ you have twisted what I said’, or even ‘must you always jump to conclusions?’ is not.