So, no, it's not incorrect to think that absent clear statements otherwise, a nice well-groomed conservative white guy who went to all the best schools and is extremely well qualified to be a Supreme Court Justice (tautologically because he's a nice well-groomed conservative white guy who went to all the best schools) would be either personally opposed to gay marriage or personally opposed to the unconstitutionality of outlawing it, because originalism or some such bullshit they hide behind.
But here’s the rub: It’s not “everybody” else who has Gorsuch pegged as being like Scalia ― it’s Gorsuch who has willingly, unequivocally pegged himself that way. He gave a major speech about the importance of the late justice and his philosphy last year and, again, publicly adheres, like Clarence Thomas, to Scalia’s philosophy of originalism. Based on that and his decisions, the Times put Gorsuch on a chart as just to the right of Scalia, with only Thomas further to the right. And, much as Gorsuch’s gay friends would like to believe otherwise, Justice Kennedy is not an originalist. In fact, his sound rejection of originalism is what had him lead the court majority in ruling that gays are protected against discrimination in the Constitution, should not be criminalized, and most certainly have the right to marry.
Every time there's a conservative judicial nominee, the "liberal media" covers it in an amusing way. Essentially, it rushes to reassure liberals that, despite evidence, he's (Sandra Day O'Connor is no longer on the court) a really nice guy and perhaps not quite as evil as we think he is. Also, well-qualified! And, amazingly, has managed to keep his views on certain issues relevant to the potential job completely secret throughout his entire legal career! Tough trick, really, and one which "both sides" engage in. Want to be on the Supreme Court? Do your best to hide your legal views on important subjects throughout your entire legal career! Remain a mystery that can only be divined by reporters talking to your friends who assure them they're really nice people who might not be interested in adding to the sum total of human misery due to some fake adherence to arbitrary legal "philosophies."