Gourcuff is a little Catholic gay boy from Bretagne who shares the same religion and same bed with Kaka. Ribery recently became a Muslim.
This was a religious fight. The convert must prove his worth to his new pals and what better way there is to do that than by hating on the gays and the Christians. Gourcuff represents both the gays and the Christians so he was a logical target.
Plus he's a mamma's boy who deserves to be beaten and insulted.