Comment by 9rx

It's not that they convinced themselves, but that they don't know how to do any better. It is as fast as it can be to the extent of their knowledge, skill, and ability.

You see some legendary developers show up on HN from time to time, sure, but it is quite obvious that the typical developer isn't very good. HN is not some kind of exclusive club for the most prestigious among us. It is quite representative of a general population where you expect that most aren't very good.