I honestly dont understand why this isn't an option.
An old pc f1 game i used to have based on the 1994 season used to have random failures and it was awesome!
It claims to be a sim but can go the entire season every season without a single retirement that isnt die to driver error.
It must be an easy function to add too, so i just dont get it. For the moaners, like you said have the option to turn it off