Totally different construction in every way. But for starters:
Maple is almost always MUCH tougher than Mahogany, it also seems to have a bit more give - it will bend a bit more before it breaks (don't push this just to prove me wrong!).
There is no headstock angle - if you drop the guitar it's not the end of the headstock with all that string tension on it that hits the ground first.
Gibson in their occasionally misguided pursuit of "vintage correct" detail gouge an enormous chunk out of the neck at its narrowest and shallowest spot so that you can get a wrench around the truss rod nut (interestingly PRS use a very similar system to adjust the rod but with much less wood removal, so it can be done - you see very few headstock breaks on PRS's for this and the angle reason).
The construction of Fender necks is such that the grain runs straight through the neck and the headstock, whereas Gibsons end up with the grain running out diagonally through the headstock - again, not exactly structurally foolproof (again, if you compare a PRS headstock the angle is very small, so this grain run out is much less pronounced)
There's a lot more reasons that people could probably point out, but, yeah, generally unless you are very careful Gibsons are basically designed to break - buy a good stand, don't just leave your Gibson sitting against your amp!