Of course they don't like unknown cryptography. It easily makes automatic decryption impossible. That means that the NSA needed scarce expert-time for each customly secured communications. No agency in the world has the ressources to pull that off for many connections. That is the reason why they love Google and Facebook, and why I stay away from these services.

But here on HN, many folks like their mantra of "security by obscurity is bad" too much. Personally, I think many of those who repeat that didn't think for themselves.