Indeed, that is what i was think when he made this topic, cartiridges were good at there time as they could hold enough data for the game and also were robust so if they were dropped or hit as kids do from time to time they would be find.
But since the time they were used they have never been develop and upgraded and are out of date, also flash sticks hold alot more data on them and as you say can be protected just as well, it just most people would rather have something that is light and small rather than something that can take being hit with a hammer.
I have a flash stick that is rubber coated, and can take quite a bit of a battering anything a normal day can throw at it, also it is water proof as i found out when i left it in one of my pockets when i washed them.