i would have to say no... i mean, just think about games like say, Battlefield. the main selling point of a series like that is the multiplayer. the campaign is a nice addition, but it doesnt need to hold up. the multiplayer must shine, though. BF has always been about the multiplayer.
games like Halo should be half and half. both single and multiplayer need to be about equally great, because both are equally important to the fan base.
and a game like Mass Effect 3 just needs the single player to be excellent. the multiplayer was new and it didnt matter much if it was good. the real draw was the single player. thankfully, the multiplayer turned out to be great.
anyway, it all depends on the game.
games like Halo should be half and half. both single and multiplayer need to be about equally great, because both are equally important to the fan base.
and a game like Mass Effect 3 just needs the single player to be excellent. the multiplayer was new and it didnt matter much if it was good. the real draw was the single player. thankfully, the multiplayer turned out to be great.
anyway, it all depends on the game.