I'm a bit late to this - but IMO adoption is rarely a simple solution - but also often not presented as an option at all.
I can well believe how traumatic for the birth mother it could be.
Having said, when I had an abortion when I was 18, I was the one asking my GP about adoption, and both he and my then boyfriend (who was there with me and the GP the whole time) strongly argued against it. I was made to feel that the option really wasn't there, and certainly not if my boyfriend disagreed. I was encouraged to feel that my boyfriend's decision (or rather, veto of my decisions) was just as important as my own feelings, and that both keeping the baby and adoption were not allowed.
I am very strongly pro-choice, but if we are going to have abortions available we need them to be presented as a proper choice - not something you're either persuaded out of or hounded into. I'm sure there are many women who were persuaded to have babies they didn't want in my situation, though.
IMO it's not really about whether these people agree with abortion or don't - on both sides of the aisle you can find an attitude towards pregnant women that boils down to 'it's very simple, and you don't matter at all'.
We need to get rid of that attitude.