I didn't get that at all! I think Juno was taken with Bateman's character because she saw him as a real cool older guy, and he was perhaps a little flattered. As she got to know him, she realized that he was somewhat shallow and immature, and that it was his wife (who at first seemed like a typical yuppie) who really cared about the baby. I think that the whole relationship between Juno and the couple helped Juno to see past first impressions in her perception of people, to "grow up", if you will.
Very good assessment.
And Sonic Youth isn't "just noise."