Men are the "strong" ones. They're the impregnantors of women. Men enjoy sex, not women. If a couple can't get pregnant, it's a woman's failure. These are all things that are slammed into our culture, though a couple of them are being pushed away. Hence when an unplanned pregnancy occurs "well, why didn't the MAN (the strong, impregnating fertile sex-enjoying partner) take care of that!" comes to mind in a committed couple and "stupid slut should find herself a man and not have sex with random guys" comes to mind when it's a single woman.
No, not everyone will thing these exact things, but a surprising amount will.
A woman cannot become pregnant alone. However, she gives BIRTH alone. She CARRIES alone. The decision ultimately rests on her even if the man and woman both agree about an abortion because while he could only talk about it SHE decided to go through with it.