Why do the wii controllers suck?

i sort of think the wii sucks. but now that i think about it, its not really the console i hate, its the crappy controllers that came with it. i mean the buttons are sometimes hard to use, its hard to move around, the sensor bar is sometimes way too sensative, and a few other things thats wrong with it. the thing about the sensor bar, if you make one false move, you're screwed. i know on the wii, it accepts gamecube games and the controllers for it. with that last sentence, heres what i dont get. why didn't nintendo keep the same concept for the controllers they had for the gamecube, and use it on the wii? then the controllers wouldn't be so hard to use, and i wouldn't be asking this question if that actually happened. i think this will be the last time i buy something from nintendo.