You may learn manners in FFXI, but in WoW, you would learn some passionate phrases, and I mean flaming, jargon, slang, even 1337.
In FFXI you are inclined to group up with people to advance, in WoW, its more about not getting abused and analraped. I've played both games, and I must say, FFXI is a great one for PvE, but WoW has such an amazing PvP system. You know, if you're a passionate gamer, you will surely have this sensation of camraderie, and often go: "Look, he's grinding, lets get him from behind (well, as a rogue thats what I'd do).
It depends on playstyle. If you're the super fair person who is aware that other people pay for this, and its unethical or whatever to gank them when you're 30 levels higher, sure, WoW is probably a poor choice, but hell, have I ever ganked and been ganked so much in any other MMORPG in my life hahaha...