This is a good post and thats where I am headed as well. The developers come and ask opinions, etc, but they are still following their own agenda. Take NCAA football. Spent(Wasted) countless hours on trying to fix the game with sliders only to discover the sliders were broken. So we tell the developers and the game ships with broken sliders again. But it has alot of new features that I will never touch.
Last year I was upset because they already had my time and money by the time I knew the game was broken. This year, they don't have either yet, sans 10 minutes that I played the demo for. So I really have no right to complain if I buy it this year. I know their MO and I know what I'll be getting.
The sports games try to add to many gimmicks each year. Its silly. Fix the core gameplay, thats all we really care about.
15 or 20 years ago Tecmo came out. Then Super Tecmo Bowl, Then SPTBII, Then III. All they really did was add stat interfaces some playbooks, and new rosters. The gameplay was honed, but not drastically changed with gimmicks. Thats what I wish games would do. The commodore 64 followed this same model with many games. If you had a good game, you didn't break it, you just made small tangible improvements and gave new rosters.
There aren't going to be a whole lot of things left to do that will bring a huge bang and increase fan base at least with sports games. There is no WOW factor. To a casual gamer 2010 looks exactly like 2009 and that pretty much goes for all sports games accross the board. Wow factor was Tecmo keeping stats. The day of the notebook was gone. Huge for me.
Best thing you can do is when things start feeling stale, take a few years off. I didn't buy a baseball game since MVP 2004, bought a PS3 and the Show this year, and WOW.
But at the end of the day, these are just games, meant to entertain and at the point they become stale, do something else. Probably alot of things out there you'd enjoy more, give them a shot and then come back to gaming in a year or so and I am sure by then, something will WOW you or you'll just find that you like other things better than video games.