In my defense:
1) There's definitely an element of "if the user can’t find it, the feature doesn't exist" with downvoting here.
2) In practical terms, downvotes are so extraordinarily rare on HN that they almost don’t exist.
Anyway, I'm encouraged that downvotes exist on HN, but the threshold could be considered so absurdly high that they're nerfed into oblivion.
And they don't exist for article submissions, which is problematic for all the same reasons I listed in the blog entry.
There aren't article downvotes-- but there doesn't seem to be a need for them. The moderators kill stories that are plainly inappropriate, and the ranking algorithm makes it difficult for things to reach the front page without a decent number of upvotes in a short period of time.
My point is: this is an interesting and subtle topic, and it might be in your best interest to study it in some detail, rather than just glancing superficially at what others are doing and forming conclusions thereupon.