The crucial difference is that the medical profession, for the most part*, has gone to great lengths to think through their procedures and requirements as they might apply to people with disabilities. When I had a dislocated hip, no one expected me to climb out of bed and walk down to radiology and get myself on the table. If you had a deaf patient, I'm sure you wouldn't give them verbal instructions about a prescription. If you had a blind patient, I'm sure that you wouldn't ask them to read a release form.

Yet TSA requires that people walk through a WTMD without considering people who rely on canes, walkers or wheelchairs. They require people to stand in the NoS with their arms up (or for a patdown with their arms out) without thinking about people who can't stand at all, who can't raise their arms, or who have poor balance. They expect everyone to be able to remove their shoes while standing. Confronted with an ostomy bag or an adult diaper or a defibrillator (which turned into a back brace and then into a money belt) or someone with autism or Alzheimer's, far too many of TSA's finest stand there frozen, not knowing what to do next. And that is clearly because TSA HQ has not considered (or has not adequately communicated) a procedure for dealing with these things which are, in fact, not all that unusual.

Heck, even at Subway last week I saw a sandwich-maker adjust to a deaf-mute customer who was pointing to what he wanted instead of answering verbal questions. It's not rocket science.

*We won't mention the nurse who was so insistent on changing my dressing that she dislocated my hip. She obviously had a deadline to meet, and it probably would've dislocated anyway. I was drugged to the gills by the time my surgeon got to her, but RadioBloke said the chewing-out was pretty impressive.