I've heard of some horrid incidents involving people who think "disability" means "confined to a wheelchair" or "blind", and therefor anyone who isn't one of those things is scamming the gov't and cheating them out of a parking place.
About TV shows... on the one hand, I understand it can be difficult to treat disability (in a recurring character) as anything other than a soundbite, unless it's going to be so overwhelming the character is defined by it. On the other, not mentioning them makes TVWorld even more an attempt at white-male-uppermiddleclass-healthy-goodjobs utopia.