I'm not sure how far that can hold. That works if you believe that the government, regardless of which politicians are in power, is doing good work in good faith. I might think that (for instance) universal healthcare is more important than airport security and we'd be fine with pre-9/11 airport security standards, but given that that's not happening, I still support making airport security more effective and more painless.
But if you fundamentally disagree about whether the government should do a thing—like, say, whether we should move towards amnesty or deportation for people who have illegally immigrated here—it doesn't follow that you should say "Fine, if we're deporting people, at least we should deport them well." Or if you think it's immoral for government to fund abortions, you wouldn't conclude "Well okay, at least we should do a top-notch job of funding abortions." Would it not be better for government to do its job poorly?
18F in particular seems like it is prone to the same danger always present in private-sector tech: technology helps social changes happen faster and more effectively, but it has nothing to say about whether the social changes are good or not. Technology enables us everything from unbreakable encryption to trivial government surveillance; it has no opinion on whether unbreakable encryption or trivial government surveillance should exist. If you're worried about that, you either need to move out of pure technology development, or you need to impede the production of dangerous technology (which is guaranteed to be a losing battle).