I don't really see the problem as long as the multiplayer doesn't come at the expense of having quality single player. For instance, games like NSMB Wii and Borderlands 2 are still a blast to play in single player, the multi just makes it even more fun. But I never felt like the quality of single player was compromised in those games. I think if anything, we're trending towards more games like those with equally enjoyable single and multiplayer.
What I DON'T like are situations like Modern Warefare/Black Ops where the single player is very short and feels more like it was rushed in favor of a more robust multi. Now the multi is still a lot of fun, but when I buy a game I should expect the single player to be fun in its own right, to the point where it could be a stand alone game without the aid of multi to give it its appeal.
