The compulsion to label & belittle gay marriage opponents

Gay Patriot's B. Daniel Blatt looks at...The compulsion to label & belittle gay marriage opponents:

Perhaps the most depressing thing about the debate on gay marriage is the dedication of gay marriage advocates to demonizing those who oppose state-recognition of same-sex marriages.  With their childish “No H8″ campaign, they contend that people oppose their view because they hate gay people.
No, there are, I grant, some folks who oppose state recognition of same-sex marriages because of their animus against homosexuals, but they do not represent all such opponents.  Many oppose such recognition because they believe marriage should be reserved for different-sex couples.  Indeed, a good number of these folks (but, alas not all) support state recognition of civil unions, similar benefits, different name.
Should we call the legislators in Rhode Island and Illinois “haters” because they moved forward to recognize civil unions for same-sex couples without calling them marriage?
In fact, some who oppose same-sex marriage treat gay people with dignity.  Such individuals have, for example hosted me in their homes, listened to my arguments, stood with me in hours of difficulty and even let me play (unsupervised) with their kids.  They know gay people aren’t demons; they don’t disapprove of us, it’s just that their understanding of marriage differs from that of gay activists.
Which brings me to the Senate Judiciary Committee Hearing earlier this week on the Respect for Marriage Act, a bill (that I support) which repeal the Defense of Marriage Act (DOMA).
While I believe Senator Charles Grassley (R-IA) is wrong to oppose the Act pending before the current Congress, he’s spot on when he takes issue with another supporter of the measure:

One of the witnesses before us today says that DOMA was passed for only one reason: “to express disapproval of gay and lesbian people.”  I know this to be false. Senators at the time such as Biden, Harkin, Kohl, and you, Mr. Chairman, and Representatives at the time, such as Schumer and Durbin, did not support DOMA to express disapproval of gay and lesbian people.  And neither did I.

Instead of demonizing DOMA supporters and questioning their motives, we should be challenging their arguments.
All this leads me to wonder — and not for the first time — why certain gay marriage advocates insist on seeing all those who disagree with them as harboring some kind of animus against gay people.

Because it's easier than making the case for redefining marriage?