It seems like a new round of "Gay" controversy is circulating again

First, we have Rick Perry's new book is under fire because, of course, the Boy Scouts are "bigots, albeit with good intentions" that should not receive public funding or access to public buildings for their view. Needless to say, this is patently ridiculous.

Now, we also have reports that Obama intends to work towards the overturn of the Defense of Marriage Act.

Now, I don't believe for a second that Obama aspires to be the "first gay president" a'la Bill Clinton/the first Black President. What disturbs me is:

a) Even in the most liberal of circumstances, a given state should not be forced, via the "full faith and credit" clause to recognize a marriage that is illegal in that state. This would be a huge blow to that state's sovereignty, and basically the main reason that a "marriage amendment" could prove to be necessary.

b) I happen to believe that homosexual behavior (between consenting adults) should not be criminalized by any means. That said, I do believe that said behavior is harmful to society and attempts to "normalize" this behavior by re-defining marriage and forcing acceptance by states who continue to oppose gay marriage is unconscionable.

I've advanced such opinions before, and I've seen others advance similar opinions. Every time that happens, people either a) spout the "live and let live" argument (which is a specious argument - live and let live does not include changing the definition of marriage) or b) start talking about the mythical "gay gene" that will soon be discovered (which, IMO, requires just about as much religious-style faith as human-initiated global warming).

Why does being opposed to the normalization and creation of a new class of rights for what is, by definition, deviant human behavior, automatically classified as rank bigotry and fear-mongering?