Mass Effect 3's multiplayer. It's not exactly dead, but it could be more populated. The multiplayer of the game, I think, is a hidden gem. It's pretty good, but a lot of people dismiss it because they think it would probably be tacked on. I think it's great. There is a lot of strategy to each character and map. But this is one of Bioware's earliest entries to multiplayer, and there are some rookie mistakes. Flawed matchmaking, networking issues, the "pack" system means that 75% of the time you are using the in-game credits, you are getting something that you don't care about, don't want, or just don't need, all of that combined with generally few maps, and free DLCs added MP maps, true, but for some reason, they are rarely played in matchmaking sessions. It really sounds like it would be better with friends, but none of my friends play Mass Effect 3, except for a few, and those that do just hate ME3.
It doesn't help that EA dropped ALL support for the multiplayer component and it generally lacks any cheat protection system, which means cheaters can cheat and no-one will care. I bet one of those days, EA will shut down the game's servers too. Very unfortunate. If whoever reads this has Mass Effect 3 and never really got into the multiplayer, try it out again. It takes some time, but it can be really fun. I just hope DA:I's multiplayer is just as good, if not better.