In all fairness, it is a common thing in almost any PvP based environment across many games. There has always been, and will always be a small handful of people in a community that feel the need to spam emote like it gives them +10 toughness IRL everytime they do. Heck, there are even addons for some games that will do it for you upon landing a killing blow.
I have only been back a week, and have seen alot of people do it. Guilded, unguilded, large guilded, small guilded, Imp and Pub. It is a reflection of a player, not a guild as a whole. Even if there are multiple people from one guild. And alot of the time, it will be a PvE'r, or someone fairly new to PvP in general. Or just that whole, 'Wolf pack" mentality.
Trick is to brush it off and just laugh at them knowing they only look like a moron.
Edit:
Mmm, very valid. It is a proven method. Back on Dalborra, good ol Mosh.... Wasnt an emoter, but would talk so much smack out the ***. Few things with that, it worked, he had a whole server either love or hate him, regardless, he was a constant topic of discussion. But he was 'one of' the best sents around at the time. And actually not a bad guy, but he would get into peoples heads to the point it effected how more casual players looked at the game.