The same reasoning that leads Justice Scalia to conclude that the Framers' ignorance of cell phones and the Internet doesn't resolve questions about "the freedom of speech" should also lead him to the Framers' ignorance about the nature of sexual orientation. If one is going to be an "originalist," at least one should be consistent about it.
DOMA clearly violates equal protection, but the Supreme Court could repeal it on more technical grounds, ruling either that House Republicans lack standing to defend it, or that it is an attack on states' rights. But either of these less desirable outcomes would still be a victory for marriage equality.
Bigoted people of all stripes and sizes will continue to cling to their prejudices and sadly, they will even demand that their intolerant and inaccurate beliefs be the standard by which all of society lives. It's time to call them on their hate and stop equating them with valid and informed stances.