If it is a dead body and it is being cremated you take it out so it doesn't explode in the crematorium. I say this as a former funeral director who had to remove them.
Thus begins one of my favorite Ian Banks novels, starting with exactly this event.
Would you have to remove the joints as well then? How are you meant to properly dispose of something like a knee or a hip?
That all is significantly more expensive than saying "you hand us a form telling us whether there's a pacemaker or not, and if you fuck it up you get in trouble."
Fair point on suing people probably being cheaper, though. -.-