My power window passenger side switch, and the drivers side passenger control switch, have both stopped sticking on up or down, the drivers side still works.

Now, i searched and found out you can "pop?" the switch area out, and there's a bearing and two springs or something.

But my question is, apart from perhaps a more detailed fix, is WHY does this happen?

 

They just weren't built to last. I've gone through a couple in 6yrs.