The pronunciation of C in Spanish is context dependent. Before I or E, it shares the same sound as S. Before A, O, or U, the same sound as QU.
Or how about G? It makes one sound before I or E, another before A, O, UE, or UI, and yet another before UA.
Lots of folks think their language is simpler, but it's only because they can follow the rules so well they don't need to actually know them.