My guess is that some folks are just here for the links, and don’t know who’s on the team. See a comment that doesn’t look like it contributes to the discussion? Downvote away, heedless of the author. And maybe that’s fair. But once a post has been downvoted once, it seems much more likely to be downvoted further, even if the original vote was unwarranted.
I can understand the confusion and your point. Paul graham is PG and his posts are always rocketed to the top. But, you can always check the profile (which I do often to get a better perspective on people).
Checking someone's profile is great because you can see their post discussions and comments to see if they're genuinely an ass or if they're geniuses you can learn from all of their other comments.
There's nuggets of gold in comments. It took me a year after I started reading HN before I really learned to value the profile and comments function.
