Is there any point to Tourism in Multiplayer?

[Florian]

I'm trying to win a cultural victory in a game with a friend and five AIs, and the percentage keeps going the wrong way with my friend. It seems it's just too easy for a human player to defend against it. Meanwhile, I keep getting attacked by AIs who have Friendship Declarations and Research Treaties with me, even a Defensive Pact recently, and I think this crazy behavior must be a reaction to my growing cultural influence over them. It seems I can never win this way, and I am just making problems for myself. What say the veterans?