It's often really hard to judge how skilled you are at something. https://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect is overblown, but being able to say do a crappy weld in 4 hours that a competent person can do better in 15 minutes is often just dangerous. Many a handyman has caused 20,000+$ worth of damages or gotten someone injured.

That said, hobbies don't need to be productive and half assing something is often good enough. Yes, a simple wedge doorstop may damage the door, but well sometimes that's just not an issue.