You know, people ReMix game music for a few reasons,
1. Its awesome music, and the game has a great OST
2. It could be there favorite game, and like fans tend to do, is change it around to there personal style.
3. To get the feel of new music, VG or not. Play a song from Seether or something, and you liked it so much, you wanted to add and maybe change something in it to experiment.
My third point is definitely appreciation of music. You love there music so much, and enjoy it so much, you play with it and maybe make a personal style of yours. But at the same time, you appreciate what the artist(s) have composed to make that song.
Its not like. "Wow. This song sucks, I'm going to make it sound better" you make it sound thats where you come from. That is NOT why songs are Remixed.