Overstated. The explosive decompression stuff you see is hollywierd special effects.
Remember a bomb went off in a 747 cargo compartment and blew out the side just ahead of the wing root. Only the passengers immediately adjacent to the blowout and an unrestrained flight attendant were extracted from the aircraft, the passengers still strapped in their seats.
In another unrelated case, the cargo doors of DC 10s had a nasty habit of blowing open in flight. It did bring one plane down but another survived while the entire rear deck structure sagged but didn't give way.
Finally, remember the Aloha Airlines 737 that popped its top? Some people died when extracted but the plane made a safe landing.
A bullet in the window or fuselage will just make an annoying whistle.
NNNNNNNOOOOOOOOOOOOO!!!!!!!! Not an annoying whistle!!!!!!
The terrorists have won.