I suspect what you may be seeing is someone who is related to a disabled person, or drives the vehicle for them. They assume that since it displays a disabled placard or plate, it's ok for them to park in a disabled spot. This of course is only legal if the disabled person is in the car with them. In my state, we are issued a wallet ID card with our name, & the number matching the plate or placard. If a cop suspects you're not entitled to disabled parking, & you don't have your wallet card .....you're busted. I have seen the type of thing you describe, Ross, & it really bugs me. Especially when they take the last spot, & I end up walking a long ways.
For me, "Getting Lucky" is finding a good parking space at Walmart.