[the OlLine Rebel]

One definitely needs to defecate. No question.

Walking is also quite necessary. In the wild, one would be a sitting duck waiting for predators. Aside from that, being moved is needed to ward off pneumonia and atrophy.

No comparison. Common sense, please!

[Trailerpark Badass]

You can defecate into a bag, through a hole in your torso; why walk when you can use a Hoveround?

All you offered was your own definition of need, which might seem like common sense to you, but who cares?

The more rational standard of treating a non-functioning, or malfunctioning body part or process seems adequate enough here.