I welcome disagreements, but the moment it goes ad hominem I clock out like a chuckee cheese employee when the buzzer goes off.
Discourse today has become for the most part full of "I got you moments" and ego stroking. So when I detect that's the intention of the person I'm having the disagreement with. I got no interest at all. I'm not going to learn, he/she is obviously not interested in perspective either.
And what do you know? I've never flagged for disagreements...
Generally when people resort to personal attacks they have either lost the argument or unable to think of why they should win.
The only times I flag for disagreement is of reward for me ;)
.....sometimes people just jump in feet first even though they know they are not going to win, the argument had already been lost in their view a long time ago.
I like to play Devil's Advocate so I don't mind this. Some people just like to double-down because they can't face losing.