First, these are not great lengths when all you need to do is download and install an application.
Second, some people don't get as much kick from playing a game as from dominating other players. They want to win the game in any way possible, but don't consider winning fairly to be any more satisfying than winning with cheating. They might be in denial over their abilities and use cheating to feel better. They don't feel any need to be courteous or fair. These are people who, when they loose a game against you, will say "fuck you" instead of congratulating you.
Don't try to find logic where there isn't any.