1) $500 Diag? You really need to find a new dealer, they are not all created equal

2) Every automatic transmission vehicle going as far back as I can remember has a shifter lockout so you can't move the car out of park if the key is not in the "run" position as a safety feature and by extension every car has a override hole somewhere in some form or another in case the car has to be towed and there is no key available, not because they are planning for it to break.

3) I have never heard of anyone else having an issue with this part and I certainly haven't and my Aveo is 10 years old this year. I would bet that there is something else out of whack in your system causing the part to break prematurely, I would look into hunting down what that cause is.

4) Just an FYI your whole car was built in Korea, its basically a Daewoo sporting a Chevy bowtie.