Apple's market strategy was already primed towards a privacy-focused stance, since their profit center is selling physical devices. Thus, when privacy becomes a Big Deal in the world, Tim doesn't have to push hard to get Apple to line up with his beliefs. If Apple had been an advertising-focused company before Snowden, I doubt we'd be seeing as hard a push as they're giving right now.
That being said I can totally believe that he genuinely believes what he says. Actually I'd wager that most tech people, including at Google and Facebook, see that we're having a problem with "big data" and the compulsive profiling of their users. The potential for abuse is tremendous.
Regardless of ulterior motives I think we should rejoice, having a behemoth like Apple taking such a clear stance on this issue could generate enough momentum to have an actual change in mentalities.