That's the problem with paralysed people. If their paralysis is gradual they would be able to commit suicide, not difficult to knock yourself with pills and a few drinks at a time when no-one else is going to come in. Which I'm not advocating! Merely being pragmatic.
It must be very difficult indeed to assist a suicide, I'm a believer in helping people to spend their last days comfortably with every medication available. Not the same as administering a dose you know is final. It's hard no matter you think it justified. I've read the Dignitas clinic has a cold and hard atmosphere even allowing for the staff having to be detached.
There will be people who want to do it & like doing it and as well as enjoying their job, they're making a good living. Imagine doing that for a career.