Those "Daddies" are aware of the history of the mother, they know what they are getting into,so they choose and deserve whatever comes their way.
Also, "disabled" is a big word. Some people can have disability and also have great qualities, be geniuses or whatever (see the Hawkings scientist dude). I read a pro-life advert that read:
"Q1: If you knew a woman who was pregnant, who had 8 kids already, three who were deaf, two who were blind, one mentally retarded, and she had syphilis; would you recommend that she have an abortion?"
And if you said YES, then it said: "Congratulations, you just killed Beethoven."
So I guess the point is you have no idea about the future of the kids in reality, and everyone deserves a chance to have a kid if they want to, in my opinion. Ofc common sense would dictate not to make babies sometimes, but forcing people in that regard is wrong.