I've talked before about how much I detest simspecs, because they evoke fear and pity much more reliably than empathy,

I'm the same with plopping someone in a wheelchair for an hour. It isn't useful because all it teaches them is to be scared of all the things they don't know how to do, and they know it'll be done with in a few more minutes. It would be much more useful if we could stick them in the chair for a month, because then they'd start to perceive it as normal, not freakishly different, and they'd start to understand the differences between what you can do in the chair, what the environment prevents you from doing, and what the people around you actively stop you from doing. And as you mention for simspecs, all the extra energy you have to use to cope with these.

OTOH I do think there is one thing plopping people in wheelchairs is useful for - teaching them how bloody uncomfortable rolling over cobbles is!