Oh, I agree, I only play the campaigns. When I'm done there's usually a new one out. The last multiplayer game I played a lot was Wolfenstein and I was pretty good at it. Remember the Omaha beach map? It was really great.I'm playing (when I have time) Modern Warfare 2. Next up is Black Ops.
Call of Duty games are the WORST multiplayer first person shooters of all time So unbalanced, so camper friendly, not teamwork based, etc. Campaigns are okay though. This humble opinion was developed over the course of many years, I've been playing shooters avidly since Wolfenstein 3D, and Doom.
I should find a server for old fogeys, it isn't fun having to listen to kids being stupid when playing. :D