God, Jimquisition nailed this on the head this week. The reason Uncharted needed multiplayer was b/c Sony lacked any decent fanbase for MP in the shooter dept (as far as system exclusives), at least, that's how I read it.
As such, ND created a competent MP mode. Now, if they are doing this b/c they LIKE it, more power to them. But more and more, I can't help feeling that MP is getting tacked on.
To paraphrase Mr. Sterling: I'm not buying Tomb Raider to play Gears of War, b/c I already have Gears of War.
If we are approaching games as a service (which is utter BS), and price points for said games are the same, the only way I am converting is if the "service" (in this case MP) is actually providing me something better, something I don't already have, or is more economical.
Thing is, I don't want resources put into SP to adversely affect MP. Whenever you have a concentrated story driven SP, there usually isn't space in the original vision for MP.
For example, tell me EA's googly eyes for MP (among other things) didn't scuttle Mass Effect somewhat. You can't turn an RPG into "Madden but scifi" and expect good results.