People that like competitive online games tend to get far more playtime and longevity out of a $60 purchase than your average single-player game fan does.
It seems quite common to see people putting multiplayer as some less important/optional 'gamemode' compared to the single player, but I think that perception needs to go away. A game focused entirely on multiplayer shouldn't be considered any less of a game than one focused entirely on single player. Its just a different type of game.
I agree Seanspeed (Forza rocks!). I myself wouldn't pay $60 for a MP game as my internet sucks, but it is funny how people are happy paying $60 for CoD or Battlefield but not $60 for Titanfall. How the hell does the tacked on SP in those two franchises justify your purchase of $60? If MP is your thing, then Titanfall will deliver on that front, and MP can be played for hundreds or even thousands of hours, not a couple of 10 hour playthroughs (if you are lucky).
I'd argue that MP games offer more value than most games, but unfortunately I never really play online so it doesn't work like that for me.