I stopped using reddit because of this. I've no idea about the credibility of the authors, their intentions and their motivation. When I'm listening to someone's opinion, I'd like to know more about them, so I can decide for myself how seriously to take it.
This outlook is alien to me. I'm quite the opposite; I'm happy reading and judging anonymous comments purely on the strength of the argument being made there and then (although I don't ignore the background and history of a commenter when that is available to me).
Not attacking your point of view; just very interesting to see an approach described so different to mine.
I only look through the post history of someone if I feel they have a particularly interesting outlook, or if they're batshit crazy and I'm a bit bored.