A lot of games are just grinding, and cheating reduces the grinding. Usually it makes them more fun but sometimes it doesn't, in cases where the game is terrible to begin with. After a while cheating is more fun than the game. One could also look at Twitch streamers and ask why the people watching don't just play the game; the answer for a lot of games is that the games are incredibly difficult and the streamer can get through a level in a few hours while it might take the viewer months.

I don't think money enters into it. People just do weird things, like painting miniatures or climbing Mt. Everest, and hacking is another of those hobbies.