True but she is the biological mother too.
That's like saying teens giving up their babies for adoption shouldn't want them to go to good homes.
Being a surrogate and giving the kid up for adoption are different. When you give someone up for adoption it is because you could not take care of them. When you surrogate, it's something you sign a contract for. You are willingly lending your womb to conceive someone else's child. You give up any parental claims for the baby. It is merely a highrisk job. In most countries, you get paid handsomely for it. I have a friend who is a surrogate and she gets paid more than 20k USD for it. If you are going to be a surrogate, you cannot feel affection for the baby you are carrying. If you can't do it, then don't be a surrogate.
It's not your baby. It's someone else's baby that you are agreeing (and usually getting paid) to carry. In more developed countries, the surrogacy is handled by a company that screens the surrogates and the families. In general, it's a very formal process though this manga doesn't get deep into that. Teens giving up their babies for adoption is a whole different context because they didn't willingly get pregnant. Being a surrogate you go through a legal process to get artificially inseminated for someone else. It is a conscious decision. When you rent a house you have some rent rules (like no illegal activities in the property) and you do a screening before you rent out the place. However, that does not give you the right to invade the people you are renting to afterwards to see if they're "worthy". You already made the decision. If you are renting your oven, then you cannot change your mind halfway through and claim the kid. The womb is yours, but the kid is not.
I don't think this woman understands how surrogacy works. Her acting like a judge to see if the dad is "worthy" of the baby is wrong. She relinquished any parental claims on that child before she even conceived.