How many people play MP vs SP?
Devote the % of time to development using whatever that percentage is.
This really frustrates me. They should devote however much time it takes to get it to the good quality level that the name Firaxis
should embody for BOTH parts. Having more people play your game single player is
not an excuse to release a shoddy multiplayer tacked on, cos then it just ends up a selling point rather than a genuine gameplay experience and you are deceiving your fans.
If they end up with another multiplayer that's bugged beyond belief like civ V's even after Brave New World they are going to piss off the ever growing multiplayer crowd, and they really can't afford to keep pissing these people off.
I managed to draw in 15+ people to playing Civ V, and they enjoyed it single player for varying amounts of time. What kept us playing together was multiplayer, but it was next to impossible to genuinely have a game of it, especially as you added more players because the multiplayer support in civ V is, for lack of a more appropriate word, *$&£. It has sadly pushed away a number of my friends from buying what i know will be another fun game, but sadly cannot confirm will be any less frustrating an experience in multiplayer.
TLDR: If you are going to include multiplayer, actually make it work before you release it
