A hoarder doesn't just keep things that they like or that are important to them. They keep everything including garbage. If you don't have half eaten cheeseburgers and empty big gulp cups mixed in with all your Christmas stuff then you are FINE.
I didn't see the show you are talking about but based on what you have posted I believe it was about something totally different. The people in the group sound like insecure people who are trying to "make" themselves happy by buying a bunch of materialistic junk. It's the classic "keeping up with the Joneses" scenario. They have empty lives and are trying to fill them up with big houses, fancy cars, etc etc. This is totally different from pursuing a hobby (especially one that brings joy to others) even if you end up with a lot of "stuff". The people in the show need to realize that happiness is not something that you go out and buy or that you have to find or acquire. It's more like an attitude. It comes from within.