I don't think you're reading it as Paul intended or as Christianity has had revealed, ZC.
The logic is: Since "love" does no harm to its neighbor, love fulfills the law.
That's quite a bit different than "be a good person."
Also, the love mentioned is not romantic love, erotic "love", or even brotherly kind feelings. It's best defined as sacrificial giving, is best exemplified by Christ, and is translated "charity" in Old English because of its difference from those other kinds of "love".
That said, this love took Christ to the cross and you can't argue against that kind of love, can you?
Rom 1:27
27 In the same way the men also abandoned natural relations with women and were inflamed with lust for one another. Men committed indecent acts with other men, and received in themselves the due penalty for their perversion.
NIV
You're assuming that chr*stianity is true (you know, like evolutionists assume evolution is true). Your assumption is faulty.