I am much in accord with your views on this, and very unimpressed with the Slate article on the subject, linked in the linked thread, wherein also see Gaffer's comment. Really, the reduction of gay relationships to sex is an ugly and pervasive bit of homophobia—nothing more or less.

As for Bernie's and Ert's figurative ages, when I was of Sesame Street-watching age I, too, perceived them as much closer to grownups than to kids; not only did they have a house, fer crumb's sake, they had agency. They read newspapers. And they didn't bicker, they argued. And they got to eat cookies whenever they wanted (agency again, but bears special mention).