I played gw2 for 1 month and quit after getting my mesmer to lvl 80 because there was a serious lack of content in that game. For those that did not play gw2, once you hit level cap you literally had nothing to do unless you were interested in WvW or pvp. The only thing that enticed player to continue playing the game was to grind for your legendary weapon.

http://wiki.guildwars2.com/wiki/Legendary_weapon

Imagine after getting your soldiery weapon you have to grind 100 atmas, do 20 animus books and meld 50 materia just to get a reskin or a glow with the exact same stats as your weapon. Sounds fun? No.

GW2 did not have horizontal progression. They have no progression. They have no hard mode raids and their pve end game was a joke. their hardest content was probably world bosses and fractals. I can't even believe you want this p2p to adopt a system used by a f2p game. Yoshi has clearly stated they created this game using inspiration from wow. There's really nothing to debate here.