The game is a squad based shooter that involves mixing the team's different abilities. Competitive multiplayer might not make sense but co-op, even a horde mode, wouldn't be a stretch. Actually could be pretty cool.
It's not like Dead Space 2 where it doesn't make sense. Even then, it didn't mess up the single player at all. There's also Uncharted 2. People seem to like that game.
I look at the Splinter Cell series introducing multiplayer modes to a stealth game and that turned out great. Apparently multiplayer in Assassin's Creed Brotherhood was good and didn't spoil the single player. There are few examples of multiplayer actually hurting a game. It's usually just there and a waste of effort.
I wonder if anyone still plays Condemned 2 multiplayer