Because there are people who are willing to spend an inordinate amount of time delving deeply into a hobby, and these people are also the personalities who will

Because there are people who are willing to spend an inordinate amount of time delving deeply into a hobby, and these people are also the personalities who will chime up in HN one day to point out your hobby code has (1) a potential optimization, or (2) a major bug, or (3) is really cool and they would like to use it one day in one of said hobbies. If there's anything I've learnt, appreciate the wisdom of these collectors, whether to appreciate the simple design of a flower, or the esoteric nature of a highly complicated mechanical computer.