I had my first child before Parent and Child spaces were a thing, thankfully by the time the next 2 came along there were a few. DH also has a blue badge so I see it from both sides. I have on occasion parked in a P&C space if all disabled ones are taken because DH cannot get out of the car without the doors wide, or walk any real distance. But I would never dream of parking in one on my own, or with my 14 year old because I appreciate them. I would have happily parked the other end of the car park if it meant wider spaces and a safe passage to the store. My local Tesco has this just right: disabled are right outside the doors, P&C stretch all along the far side so there is a safe traffic free walkway through to the shop itself.
As for all of the 'we never had them get over yourself' arguments - we never had seatbelts, or car seats, or drink driving laws but I bet you wouldn't want to be without those now. A little consideration for others goes a long way.