I like the blog post, but I think that it is somewhat unfair against DDG since the argument works against any internet company. The argument rests essentially on two points:

1. Client/Server architecture has a single point of failure, namely the server. ( Or the network equipment directly upstream of the server.) So that whatever nasty surprise is embedded directly at the server, or in the jurisdiction the server is in, affects whoever is using the server.

2. We do not have a treat model for the NSA, they are somewhere between a usual state level attacker and Cthulhu. We do not really know, what the NSA can or can not do, can they crack the discrete log or factor large numbers? Or do they 'just' have a assorted 0day collection? Is it realistic that they can coerce anyone into revealing public keys? And if they can actually break TLS, can they also break all TLS or does this require some not insubstantial effort on their part?

So both of these are real problems and the combination is potentially undermining the trust into the entire internet. But it is not really about DDG.