not generally, but in this context, yes they are. the idea that asexual = broken rests entirely on the notion that it's unusual and possibly a medical issue if you don't want to fuck anybody. it's a rude, usually mistaken assumption that's ultimately nobody's business but the asexual person's, but that's how rude, nosy people see it. person lacking a function = person not functioning in the way other people function. person not functioning in the way other people function = strange person.