He’s saying that “pioneers take the arrows, and the settlers take the land”.

Haiku makes him feel like a pioneer again, and it sounds like the tinkering is fun.

Based on your comment, it is highly unlikely that you would have used Linux desktop in the late 90s for the same reason you wouldn’t use Haiku today. A lot of people feel out on computers, if it was just about doing work then the vintage computer hobbyists would all find something else to do.