To be honest..
Halo isn’t great. It’s not bad, It’s just not that great. It’s average. Bland. Boring.
I’ve beaten the single player campaign, and I really don’t feel any need to come back to play the multiplayer.
I have no idea why. I just don’t want to come back to it. I don’t want to have to play it on legendary. It doesn’t interest me. I don’t want to get the katana, or any of the special armor. That’s stupid. I don’t feel that much of a competitive rush in most matches. Which is amazing, because most Halo games I’m in will come down to the wire. One kill will separate winning, and losing.
The new weapons and equipment are great. Theater is nice. Forge isn’t exactly what I was hoping for when I heard Halo map editor, but none the less, people have done nice things with it, and it is fun to play around with occasionally. However, I just don’t want to play. It bores me. And I loved Halo 2. I couldn’t stop playing it. Maybe there both too alike? I have no idea. The guns aren’t too realistic..Maybe that’s it? I like the rush of the realistic setting and weapons? I loved the Call of Duty 4 Beta. I spent more time on that then I did on Halo..Hmph.
People will invite me to games. I come, I’ll play. I’m skill ranked at 14. I’m not bad..I finish first on my team most of the time on Team Slayer. I can keep up with the kids who are captains and have 1000 achievement points. People ask me about my rank. Why it’s low. Why I don’t get it up. I have no other explanation other than, I don’t play.
Why?
I don’t know. I guess..Halo is getting old for me.
I see people playing Halo like it was their religion(No I don’t mean they play every Sunday for an hour)
I also people playing other things they like, Guitar Hero III, etc.
Some still play Gears and Ghosts(Ew..Ghosts)
What do you think?
Thunderblog 
Sounds like you are an old stick in the mud.