That quote would mean that the system being unusable without RC4 is exactly the point.

It doesn't mean that a system is what its makers intended for it to do.

Yes, that is precisely my point.

“ According to an intelligence budget document leaked by Mr. Snowden, the N.S.A. spends more than $250 million a year on its Sigint Enabling Project, which "actively engages the U.S. and foreign IT industries to covertly influence and/or overtly leverage their commercial products’ designs" to make them "exploitable." ... One goal in the agency’s 2013 budget request was to “influence policies, standards and specifications for commercial public key technologies,” the most common encryption method.” —New York Times