Even when I started making games as a hobby, I kept making sure to complete my games, specifically because I was so disappointed whenever I'd find a project and it would get abandoned (or was already dead when I found it).
I also dislike bugs, so I try to leave things in a reasonable state before moving on (and if I get a report some time down the line, I'll try to release an update even if the game isn't in active development).
Not saying there aren't good reasons why certain games get abandoned, but usually it's just that the dev underestimated what it takes and doesn't want to keep it going, or they expected more money when what they are doing doesn't quite have that potential.