Amongst people that married their high school sweetheart and endured the hardships of a boring life in suburbia, abortion is seen as a kind of cheat.
They feel as though there should be some kind of punishment or consequences for partying away your 20s. If you have sex out of wedlock then you should bear the risk of having to raise a child as a single parent and have to endure the shame associated with that.
One of the basic tenets of morality as taught by Christianity, or boomer working-class polite society, is that immoral behaviour has shameful consequences. The “wages of sin”, “you reap what you sow”, et cetera.
Basically, people feel like only harlots need abortions, and harlots should be punished.