I'm pretty sure that they would have been able to come up with another non-magnetic solution if they wanted to. But it would take a lot of money and manpower to

I'm pretty sure that they would have been able to come up with another non-magnetic solution if they wanted to. But it would take a lot of money and manpower to come up with a good alternative and test it. A less elegant solution is the breakaway cable used on the original XBox controllers, which would detach while leaving the "main" connector still in the laptop.