HN style is to go really light on joking and really heavy on information. It can make for some dry reading sometimes, but it's better than Reddit where informative discussion can get drowned out by jokes, pun threads and snark.

So people tend to downvote witty comments unless they find them very funny.

Furthermore, complaining about downvotes is a gamble. The odds are in favor of receiving more downvotes if you complain, though sometimes it works out the other way. However, the odds are especially biased for more downvotes if you make some sweeping statement (or "question") about the entire community as a reason for the downvotes.