They have no way of stopping it but the relieve a lot of the workload on the two pilots who have lights and warning going off as they're trying to get the plane under control, and I hope you're not saying that excessive AoA is the only thing that can happen.
Point being, planes have grown more and more complex over time with less and less direct control of the systems, just lights and procedures that aren't as completely understood, clear or complete as they need to be.