we tend to scrutinize posts/​comments more carefully for flaws when they argue against beliefs that we hold
It seems likely that, given limited time to read comments, any given member will stick to the more controversial (and therefore interesting) comment threads, leading to an apparent piling on when disagreement is expressed.
It seems likely that, given limited time to read comments, any given member will stick to the more controversial (and therefore interesting) comment threads, leading to an apparent piling on when disagreement is expressed.