If it was major surgery, that's the only way they should ride in a car for now, as a passenger.

You still need to be in sight of the vehicle, so the car would still have to be located near the store entrance. And as this article shows, you have to have a good, unobstructed view of the car in order to not accidentally run into something.

And it doesn’t seem like you can leave your car at the entrance, which also means you are only saving yourself half of the round-trip.

You can tap a location on the map and have the car drive their... and it seems to generally respect the rules of driving in a parking lot (going up and down the lanes instead of through parking lots) - I wonder if you could get it to park itself...

If not that capability will probably be added in the near future.

Are there no dedicated parking spots for the disabled in the US?

If it's anything like the UK, plenty of non-disabled people use them regardless - because they drive a massive Q7 which doesn't fit into regular spaces, or just because they're closer to the store/school/whatever.

Pretty dispicable if you ask me, but there does seem to be a large segment of the population that just don't give a shit.

There are, and they're usually the closest spots, but picking someone up and dropping them off right in front of the store is usually closer. (Oftentimes, doing pickups/dropoffs there is explicitly disallowed, because stopped cars obstruct the view of pedestrians for drivers of moving cars.)