1) it's fast and easy to do simple modifications to an image.
2) I know how to use it well.
3) It automatically saves jpg images in a low quality format, which I need it to do for thumbnail images for my website. (for fast loading) That's basically all I use Paint for - thumbnails.
4) It doesn't take any time to load.
5) I don't want to install Photoshop on this computer b/c I'm lazy.

If I'm doing any image work other than saving thumbnails, I'll use Photoshop. It's on the same computer Maya is on anyway. (not this computer)