Why, then, even bother checking their HN karma score, GitHub commits, WoW gear score or Stack Overflow reputation points? Either their comment is useful to you

Why, then, even bother checking their HN karma score, GitHub commits, WoW gear score or Stack Overflow reputation points? Either their comment is useful to you where you live today or its not. You don't have to justify your judgement by yet another subjective. (By a... checking... 3.4 karma/comment user who was sub-1.0/comment last week; not having changed his opinions or commenting style.)