I put in a lot of hours in multiple shooters. From Gears of War, to Killzone 2, to COD4, to Uncharted 2, to Battlefield 3 to Halo 3 etc...
One thing that they all have in common in relation to DLC? All of their multiplayer modes become fragmented whenever a DLC Map Pack drops for them. It typically works like this, you and some friends buy a game at launch. You guys get some games in, some people like the game more than others, so they'll get a Season Pass. Some may wait and see if they want DLC in the future, some just don't fukk with the game and only bought it to play with friends, and only play the game when they have friends online.
Now you have all of those mindsets going for a particular game. Then DLC comes out for the game, and now friend A who has the Season Pass gets all the new maps. He's loving it, he's obviously a big fan of the series and can play it without anybody on his friend's list on with him. So now his other homies want to play some games with him. But they don't have the new maps... so now friend A is forced to either play the default maps because his boys don't have them, or just play matches on the new shyt without his friends. The others are just left out, and all while that is going on, more playlists for the multiplayer section of the game are added meaning the community is getting split up. Stock Maps, and DLC Maps... unless the game has a huge following that can withstand that, the activity for the game dwindles. Plain and simple.
I don't know how many times I've hopped on BF3 (I'm a Premium Player) ready to go ham on some of the DLC maps... I find a nice room, then I get an invite, or see my boy playing it as well. Then we link up and he doesn't have the same maps that I have. It's a problem that Guerrilla has obviously recognized not just with their games, but with the way online gaming is set up for FPS in general. They're taking a different approach that makes WAY more sense, and some idiots are just not understanding how this is a much better model.
That's also how I know, who really gets into a multiplayer game who doesn't. Only nikkas who suck at multiplayer modes would be so but hurt over the game not having a default horde mode.