I think Xthform is actually referring to a different kind of PC than is normally used in the US context of people being "too PC", but still considering PC as a negative thing.
(For full context, a lot of rhetoric in the US considers using non-slur names and presenting minorities in a positive light, in the name of political correctness, to be pandering to those minorities, and therefore being PC is a bad thing (if you're a white cis straight God-fearin' all-'murrikan asshole male, anyway).)
Correct me if I'm wrong, but I think Xthform is actually arguing that in reality, it's being PC to pander to the white cis straight Christian American male (abbreviated as WCSCAM from here, because screw all that typing) segment of the population, and being PC in that regard is a bad thing (which, IMO, it is). If I'm reading it right, he's also arguing that Jeph ends up being too PC in that definition, to prevent his audience from attacking him too much for being too PC in the standard US definition, which I disagree with - Jeph has changed dialogue before for the sake of not offending his audience, but just about every time, it's been for the sake of not offending MINORITIES, not to perpetuate the WCSCAM's perspective. And, he's been afraid to go down storylines not for reasons of offending the WCSCAMs, but rather for reasons of potentially offending the minorities he's portrayed (just read his comments re: the Claire storyline).
Not to mention, he portrays racial, sexual, and now gender minorities in a very positive light, and he DOES explore storylines involving those people in ways that would horrify the WCSCAM. (Well, you could argue the lesbian exception to the WCSCAMs being negative about homosexuality (which isn't positive, it's creepy, but at least it's not outright hatred) in the case of storylines involving Tai's personal life, but still.)