This sucks if true.
I didn't use the c-stick primarily for smashes (even though c-stick smashes are very useful). It allowed a fantastic amount of aerial movement while I was able to throw out any aerial I want. It even allowed unorthodox movement techniques like DACUS, and it helped with SDI. It's an extra control option that gave Smash much more depth.
A example in Melee... try to play Captain Falcon, short hop with X/Y, fast fall as soon as possible by flicking the control stick down while moving in any direction you please, and then throw out an up-air with the c-stick just as you're about to land. You could probably 2 of those entire sequences within a second if done correctly. Things like that are going to be extremely rough without a c-stick.
But apart from that, another example would be to to play as Marth, short hop backwards while throwing out forward aerials. How is that going to be possible if the main stick is occupied with you holding backwards? The c-stick gave you a choice to use any aerial you wanted, while you had free control of your characters movement in the air, and that in itself allowed for such creativity in how you use your moveset (just look at how often Fox/Falco players in Melee approach forward with back-air--it's seriously one of the most useful things in Smash to ever exist).
Well, there's always Smash Wii U at least!