For some people, abortion is an issue of morality. For others, abortion is an amoral procedure (it has no value of right or wrong).
This is so easy to understand. Something that is an issue of morality for you is NOT necessarily an issue of morality for others. See my example on taking Tylenol and how pretty much everyone thinks of it as an amoral act except for some hardcore Christians.
Edit: Let me list some things that are amoral for most people: wearing skirts, taking Tylenol, dancing, drinking, getting tattoos, going to birthday parties, etc. And yet, though they are amoral for most of us, they are issues of morality for others. Include abortion on this list relative to me.