[justaguyhere]

I've also seen downvotes if I ever criticize landlords on HN, even when they are valid criticisms.

[datameta]

Not to disparage your point or the parent comment's but I think part of that is that HN operates to a much lesser degree like an echo chamber (as the majority of social network are wont to steer toward) so it might come as more of a surprise when someone disagrees. Of course I feel I should highlight the obvious fact that discourse is far more valuable than trying to quietly silence a differing opinion...