Those stalls are "accessible," not "exclusive."
Bottom line.
Exactly. I'm going to go out on a line here, and probably catch more than a little flak for it.

For public restrooms with several stalls available:
--If there is no one behind me who will need the H/A stall I will use it if it is the first one available.
--Regarding the above, I will use the H/A stall even if there are other stalls available (ie no one else in bathroom) or if H/A and single stalls free up at same time.
--My choices above aren't dictated by either a 'short' or 'long term' visit. Using the bathroom is using the bathroom. FWIW, since I have no desire to be in a public restroom one fraction of a second longer than necessary, I never 'dawdle' in either stall or public area.
Why? I like the room. I don't like having to act like a gymnast to keep my clothes off the floor and out of the toilet in a cramped stall. I don't like the closeness to others, and the extra room plus one wall stall free helps immensely. More than likely it is the nicest stall in the bathroom, and if its available I'm going to use it (unless someone that needs its special accessibility features is needing it).
I'll probably be roasted for my remarks, I know.

Please keep in mind I respect others' decision to not use the H/A stall for whatever reasons. I just ask others not be shocked or offended that others' views may differ.