Multiplayer has become the more 'acceptable' way to play games as far as the general media is concerned since it's about as close as gaming gets to being a social activity (rather than the stereotypical 'shut yourself in a dark basement and stick on the 60 hour single player while everyone else goes to play in the sun' option).
The majority of 'normal' people enjoy engaging in social activities as well as being able to play on the entertainment box thing they just spent most of their money on, online multiplayer allows the combining of these two things.
Also, compared to a lot of single player games, multiplayer is very much 'pick up and play' with very little in the way of required dedication (most games last a maximum of 20 minutes) and don't require the player to get too involved in what they're doing (if someone asks you what you have to do in a game it's much more sociably acceptable to turn around and say 'get more points than the other team' than to state how you intend to save the fair people of the Kingdom of Aldiair from the foul necromancy of the evil Wizard Zarrok and maybe loot a few castle keeps on the way, complete with virgin princesses).
In short, multiplayer is more accessable as far as games go, you don't really need to be a diehard gamer to get into a multiplayer game.
The majority of 'normal' people enjoy engaging in social activities as well as being able to play on the entertainment box thing they just spent most of their money on, online multiplayer allows the combining of these two things.
Also, compared to a lot of single player games, multiplayer is very much 'pick up and play' with very little in the way of required dedication (most games last a maximum of 20 minutes) and don't require the player to get too involved in what they're doing (if someone asks you what you have to do in a game it's much more sociably acceptable to turn around and say 'get more points than the other team' than to state how you intend to save the fair people of the Kingdom of Aldiair from the foul necromancy of the evil Wizard Zarrok and maybe loot a few castle keeps on the way, complete with virgin princesses).
In short, multiplayer is more accessable as far as games go, you don't really need to be a diehard gamer to get into a multiplayer game.