Reason I asked is because I know of a couple myself that blew their engines not because they change their Oils more frequently than the suggested intervals by BMW, but because they mis-shifted and ended up with bent valves.

Changing oil is considered to be preventive maintenance. To prevent disaster! Just as you are suppose to replace the coolant , if not could result into overheating and eventually cause a blown headgasket and or
a warped head. Another type of engine failure. Let me reiterate, FLUIDS is what extends the life of the car... replace em'.... Even the so called Transmission Life Fill. Changed them at 60K. Why wait for it to fail when you can prevent failure.
Now that's me personally on how I maintain my vehicles and if anyone else feels that I am too Anal about it or think I am my wasting money... thats my prerogative!