It's because sports game developers haven't gone into the level of AI depth that action and strategy game developers have.
AI defines how scripted the game feels and right now most sports games against the CPU are just randomized turn-based strategy games with pretty graphics. The difference is that humans have stick skills and that's why these games feel too easy.
That's the main reason I always end up in Coach Mode or just being a roster manager and letting the CPU execute... it's more entertaining and challenging than simply joystick weaving around idiots who can't take correct pursuit angles.