Nintendo manufactured the cartridge for third-party.
Make Nintendo angry and you didn't see the cartridge to sells your games.
Retailers like Toy'r us depended heavily on Nintendo products ( if I remember correctly 20% of Toy r us profits were depeding on Nintendo at that time ) so make Nintendo angry and you didn't see popular Nintendo products.
EDIT: You can undestrand why Nintendo went with cartridge with N64 now. Nintendo made a lot of good and bad decisions in its history but always trying to maximize their profits ( while Sega was obesed to be the next Nintendo, be the number one )
“In the entertainment business, there are only heaven and hell, and nothing in between and as soon as our customers bore of our products, we will crash.” Hiroshi Yamauchi
TAG: Like a Yamauchi pimp slap delivered by Il Maelstrom; serving it up with style.
