Remember that in the 80s people were used to loading games from cassette on home computers. Remember the loading time?
I went from having to wait around 10 minutes for a game to load on my Atari 65XE to much much less when i replaced it with the A500Plus.
Cartridges where not all that popular on home computers and home computer users felt they had a much more serious system with floppy disks.
Also cartriges as pointed out already in this thread cost much more to produce than floppy disks.
