He's bringing down the number of needless complaints over the long run. If he has to complain a bit in the short term to make it happen, well, that's worth it!
As it is, the fact that we're having this "conversation" at all mostly shows HN is declining in quality. I seldom complain about downvotes but when there's no comments and no obvious justification, it seems reasonably warranted.
How about this then: complaining about downvotes will invariably get you even more downvotes, and this time they'll actually be justified due to your attitude and tone.