I'm not sure that I agree that the response by Brentwood is a very good defense of gay marriage. I have always felt that gay marriage is just, reasonable, and should be legal everywhere. I have a problem comparing it to liking broccoli.
Prior to the Supreme Court decision, it was law in 30 states. The vast majority of people, including the President, have come to believe, as I do, that it is a matter of fairness and certainly falls within the spirit of "pursuit of happiness". Almost all people against gay marriage do so because of religious belief.
I believe that this sea change of sentiment is mostly a matter of understanding, education, and goodwill. It may feel good to exact a bit of revenge on someone as hurtful and thoughtless as the people in this instance but it is not how we got here.