I did the exact same thing with Call of Duty! I used to buy the game every year at launch. The single player campaigns were some of my favorite in gaming, because they were crammed with action and felt like they costs millions of dollars per second. I used to describe them as “money pouring off the screen.”
I liked the multiplayer too, but not as much as other people. And then, I just sort of faded out. When I couldn’t bring myself to finish Black Ops 2, at the time heralded as the best one ever…I knew something was off.
I bet you’re completely right and that it turns into “just a job” for so many of the people working on big budget games. I think the only solution is to slow down cycles a little bit. I’m glad that Assassin’s Creed took some time off, for example, and injected some new talent…because the new game looks like a genuinely revamped thing and not just some new art on top of the same old game.
But that’s the exception rather than the rule with most games. It’s weird because if a game is too different it runs the risk of not selling, and if it’s not different enough it has the same problem. Walking the line of balancing satisfaction for established fans while at the same time bringing in new players seems like it would be a daily nightmare for a designer.