*ahem*
3 reasons why that isn't used as the main form of media.
1.) Space limitations, it's apparent when you look at the N64 and PS1.
2.) It CAN GET DAMAGED, all media, if not proplerly handled can be damaged.
3.) What's more costly in the long run, cartridges.
Now for that question Doc.
Are all your latest inventions environment-friendly

?