Multiplayer tends to get really repetitive for me. I don't like spawning into the same map that I've already done ten times that day with the generic goal of "kill them blue guys" or "get the flag" or what have you.
I'm aware that there are other forms of gameplay besides deathmatch and CTF, but it seems like most gamers forget about those, and as a result, those are my main gameplay choices. After I've done them about 3 times, I'm bored.
Granted, campaign can get just as redundant, but I don't expect that to last forever. I expect to play the campaign once all the way through, and then maybe replay my favorite parts a few times. There are still people out there playing Counterstrike. HOW ARE THEY STILL DOING THIS? Is it like an MMO, where you just don't realize that you're doing the same thing forever?
Another thing I forgot to point out is that, when you're playing humans vs. the computer, the drive to make it "fair" is no longer present. You don't have to have even teams, or the exact same base on both sides of the featureless canyon. You can have 600 zombies vs 2 people, and that leads to a more epic feeling of winning then my four guys beating your four guys.
In conclusion, I don't think I really "get" multiplayer. Maybe someday...
- J