My dad at 50 got a disabled parking placard. He did have knee surgery, but he really didn't struggle with it about 4 months after his surgery. I asked him why he still had it - I got the impression that at this point he wanted his priority parking spot anyway. Didn't like driving around with him much after that.
I wouldn't hold that against him that much--the overabundance of handicapped parking spots is reason enough to game that one. It's ridiculous. My wife could have qualified for a placard because of her cancer and she was in a wheelchair for awhile, but we didn't bother getting one.