"Proghet" stands for "progressive heterosexual" shipfic or shippers. These are fans, almost all of them straight women, who claim that slash is "misogynist" because it "erases women." Their blithe disregard of all the misogyny in het ships, pro and fan, seems to indicate that they are yet another demographic using SJ as an excuse for shipwars.
They are also often extremely homophobic; many of them are religious conservatives. This makes them distinct from the misogynist likes of Neo_Prodigy and Sparkindarkness, who believe that all slash is the result of straight white women fetishizing gay men (an attitude that resurged on Tumblr in 2016-2017).