People with valid handicap placards can have conditions that you and I can't "see". Be careful being so quick to (mis)judge...
The thing about my dad is that he got his after he was working on the roof and fell off and broke his shoulder bone. To this day he still has extreme shoulder pain. His doctor signed off on it, since he's older and has difficulty getting in and out of his car, as well as some endurance issues (used to be a heavy smoker). He can manage it himself with difficulty, but if I'm there he asks me to help him slip his shoes on. He can manage driving himself, but it's not as easy as it was 20 years ago.
There are a lot of moving parts to the law and I'm not sure how they all work. One is that the ID card (which comes with each placard/hang tag) theoretically needs to be presented upon demand if the placard is being used. But that might not work with other parts of the law that allow its use for transport of the disabled person by another party. And he's been asking me to do that a lot recently.
My grandmother never drove before and had a disabled parking placard. It was for transporting her in whatever car she was in, and obviously none were registered in her name. Often we'd drop her off as close as possible even if there was no parking at the curb, especially when she used a walker and just an additional 30 feet was tough. Then I'd park at the closest disabled parking spot. The rationale in allowing that would be the time it takes to retrieve a car for the disabled person. At least in my state the requirement is that there needs to be the disabled person in the vehicle or in "reasonable proximity" when transporting that person. And more and more I'm asked to help transport my father, carry stuff, etc. I might drop him off somewhere and look for parking using his placard. It might even be several blocks away, but the idea is that it should be as close as possible in order to retrieve him or perhaps even him finding the car. I don't believe that I would need to be in the car at all times waiting for him to return.
I trimmed the stuff on fines, but I'm pretty sure I'm in the clear if I use it when he's on the trip. There's no definition of "reasonable proximity" but I would argue that the closest parking I can find would meet that definition.
(b) A person to whom a disabled person placard has been issued shall not lend the placard to another person, and a disabled person shall not knowingly permit the use for parking purposes of the placard or identification license plate issued pursuant to Section 5007 by one not entitled to it. A person to whom a disabled person placard has been issued may permit another person to use the placard only while in the presence or reasonable proximity of the disabled person for the purpose of transporting the disabled person.
(c) Except for the purpose of transporting a disabled person as specified in subdivision (b), a person shall not display a disabled person placard that was not issued to him or her or that has been canceled or revoked pursuant to Section 22511.6.
Disabled parking plates get interesting because it's still legal to lend out a car with them, but where the borrower is supposed to follow all applicable rules as if they weren't there.