I sometimes do that even for articles that aren't "Show HN". The oldest article on the newest page is currently 31 minutes, so if your submission doesn't get at least a few upvotes within 31 minutes, it will never be seen.

I've previously said that there should be some kind of algorithm for that page other than "here are the latest entries", such as "here are the randomized latest entries over the past few hours without enough upvotes to reach the front page, removing the entries that are on the front page, removing most-likely-spam entries that have at least one flag and were submitted by a new account, and (maybe) giving weight to submitters with higher account ages or karma scores."