Because people's circumstances are not always the same. Because the decisions some people have to make in life not always viable options for others of others - everyone is NOT the same; we're not all 5' 8', white, blue eyed humans cast from the same mould, born into the same circumstances, with all the same rights and privileges.
If that is truly your history, then your attitude towards the needy and the vulnerable is even more unforgivable than I thought. You've had poverty all around you but you are immune to its effects on Society.
I lost my first wife to breast cancer many years ago so I feel your pain. My pain is still raw sometimes.
Neither did my parents (until they retired) and nor did I. That doesn't make me immune to the hardships others face, and it doesn't make me want to defund abortion, contraception or take children away from poor families.