This is true in the same sense that grep is extremely programmable, but comparing grep to C would be strange indeed. Ethereum is a Turing complete VM, allowing you to build extremely complex systems (we, for example, are trying to build a more transparent and distributed directory for a Tor-like service), while Bitcoin lets you sort of control transactions a bit with what amount to something closer to "rules" than "programs" (due to the explicit lack of looping control structure).