it is a difficult subject for sure.

I know for me, I simply wouldn't want a friend or relative to take care of me (when I get to that point in life, because I wouldn't want to be a burden

I also couldn't do it myself. I cant cope with bodily fluids, I could do it if it was a simple case of taking someone to the toilet and standing by the door while they go, but nothing more- no way would I wipe up sick, or clean anything else from someone's body. it's just gross, and you need to be prepared for that kind of job (I have a friend going in to that job after she's spent lots of time working with kids, so it's going to be interesting how she copes)

to the question: should they do it, I suppose it depends

no one wants to send their loved one to a nursing home. apart from the fact that they are their loved one, their are stories of bad care in nursing homes... my grandmother who had dimentia was treated really badly in one (they would leave her for hours just sitting in her own filth)
if someone thinks they can handle it, then why not. I think their comes a point in everyone's life when it gets to much for the family

and then it's obviously how much the family in question can cope with

also: another factor is if the home and stuff is suitable

example: the relative needs a stairlift and the family can't aford it, or stairs is out of the question and you live in a place with stairs