The problem is you've already loaded the question by saying a fetus is a person.
This medical definition is a pretty accurate description of an embryo/fetus:
Parasite: A plant or an animal organism that lives in or on another and takes its nourishment from that other organism.
Getting rid of a parasite doesn't sound like a bad thing at all, does it?
Even more so when you look at the problems this parasite can have for the host, including (but not limited to) hypertension, gestational diabetes, anemia, depression, extreme nausea/vomiting, pelvic problems like pubis symphysis disfunction (causing chronic pain) and severe dental problems (enough of a problem that pregnant women get free NHS dental treatment).