C-stick for tilts has it's place, ryu fo instance gets a far scarier weak up tilt from it, especially on fast fallers, as he can move just ever so slightly after a tilt, and turn left or right, basically you can lock some characters with this, and if they don't save their second jump so they can escape at mid to mid-high %'s, or have an aerial fast enough to trade hits with ryu, they can get trapped even longer *coughpoorfalconcough* Which can also lead into a nasty true Shoyuken. C-stick for tilts also makes it far easier to land a pivot forward tilt as ryu.
I'm sure other characters can still benefit from c-stick tilts, perhaps not as much as ryu, but there are still some others.