I partly agree with you, but I think the order is reversed. The game bacame not-fun because it switched to next-gen and the gameplay was bad. This making it sim thing started AFTER the game became not-fun.
I personally had no problems with the madden cards. I didn't use them but I certainly didn't care that they were there (and I always used my points to buy them and see who I got)
In other sports sim games, difficulty levels has been replaced with realism -- Put forza 2 on noob mode and hand a newbie a controller and they can go whizzing around the track and have a great time. Want to up the difficulty? Turn off the "assists" and now slamming on the gas while you're still turning will have you doing doughnuts. In Tiger Woods, it's quite easy to sink 60 foot putts on easy mode, but turn off the putting assists and you can no longer do that. It stops letting you give the ball spin after you've hit it. Drives aren't quite as accurate. Core gameplay remains, but these little realism tweaks have a huge cumulative effect on difficulty.
I think Madden should go the same direction, with different levels of assists. On rookie type modes, you get a high scoring, highlight-reel every play type game with weapons, madden cards if you wish, etc. Now rather than increasing difficulty, increase realism.
Weapons go off
Fatigue goes on
Random events like botched snaps happen at a more realistic rate
Weather has a more realistic effect on play
Less frequent over-the-top animations
CPU playcalling gets smarter (not spying, just less random, adapts faster to your playcalling, takes advantage of mismatches on the field, etc)
You're playing the QB for the duration of a pass play rather than switching and controlling both ends of a pass.
direction and speed changes to
velocity (so you can no longer change direction while maintaining full speed)
the risk-factor for using the hit-stick/jukes/spins increases
And of course one could turn them on and off individually to make the game challenging yet fun for you.
Wouldn't that be fun for everybody?