I think the main reason for hostility toward GvG guilds is that they often come across as snobbish, elitist and uncaring about the server in general.
I sympathize with the GvG guilds in their effort to make a competitive mini-game mod, because WvW is not competitive in the slightest.
But from my purely anecdotal experiences both with and against GvG guilds, they log on for a few hours, crush face against lesser organized opponents, do a GvG match or two, and log off. To use a football analogy, GvG guilds play great first-quarters, but the referees insist on keeping score for all four quarters.
The scutwork of upgrading and holding buildings, scouting for enemy forces, playing off-hours, defending while outnumbered, the stuff that actual holds a server’s rating together is left to the plebes. Who rightly or wrongly, still care about the score.
Caliburn.1845, Monsters Inc.
Darkhaven>Dragonbrand>Blackgate>Maguuma>Yaks Bend>Stormbluff Isle>Yaks Bend