[CM30]

People have interests/things they like and want to show appreciation for. Hence fan fiction, fan videos, games, mods and hacks, reanimated videos, animations, etc.

Also it's worth noting that despite the memes online, the vast, vast majority of fan works are left alone and survive online for decades. The chance of a fan project actually going to waste is incredibly low, since a decent percentage of creators either like, support or don't care about fan projects based on their works, and even those that dislike them or try to shut them down only do so a minority of the time.

It just sometimes doesn't appear to be the case because 'fan project in development for 10 years shut down by [large company]' is an easy to write/attention grabbing news story, in the same way 'plane explodes in mid air, no survivors found' is for the mainstream media (with similar effects on people's perception of plane safety vs car/train/whatever safety).