One doesn't have to worry about his lament that "intellectuals" give short shrift to his philosophy.
Here, in three points or so:
1. Andrew Koppleman put it best (paraphrase): on inspection, people can see that gays can and do coordinate with each other toward a fundamental human good. (This is what makes rejections of George and his travellers' conclusions so easy for so many, not just that they don't understand his purported sophistication, aims, or good intent).
2. The moral truth of marriage, even as George grounds it ('a community of adults coming together in a special way'), need not logically be grounded exclusively in hetero-sex. (I have come up with a new way to illustrate this, succinctly.)
3. The effort to locate "gay" as nothing more than a step in the long process of "sexual liberation" is a conceptual non-starter. No matter whether or when any particular society is "liberal" or "conservative", the question of gay abides, including marriage, because of the fundamental character of gay attraction. This is one reason why his Harvard journal article will not interest "intellectuals", except as an illustration of his ability to do apologetics, not analysis. (Recall the joke about the New Natural Lawyer who only brought a liberal consequentialists with him to a dialectical drinking party).
Sullivan's reply/notice is brief and political.