OK, but they can break the glass just as easily.
They can also just put a screwdriver on the edge of the handle and whack it shattering the assembly then use the screw driver to pop the lock.
Don't mistake using the key hole as an entry point as being the only way to get inside quick.. they just use that one because they can. Eliminate it and they will just use option B or C...and be inside just a quickly.
The key hole isn't the single weak link in the fortress. There are many and a good thief knows them all. You simply cannot eliminate them all...especially as long as the car has glass windows.
A good alarm helps so that if they do break the glass or open the door, the siren sounds. But even then, they only need a few seconds to grab stuff and run. it also doesn't eliminate the damage they did getting in.