The average guy doesn't have the time to read enough about cryptography to have the sort of knowledge you're wanting. This very article debates an understanding created by incomplete and poor cryptographic knowledge.

If there's anything I've learned by studying cryptography, it's that the average person needs to invest significant resources to become a pseudo-expert in cryptography - all before they can make any meaningful decision.

Applied Cryptography is not a terribly good starting point for cryptographic understanding these days. That's just another facet of difficulty: where does one even start? Do you want a theoretical baseline understanding? Do you want the high-level, quick-and-dirty overview which only gives a summary? (That'll make it hard to make real, informed decisions...)

If we really want to make cryptography accessible to many developers, the best solution is for the cryptographic community to make our libraries and interfaces better. At the same time, there comes a point where a developer has to stop and say "this is beyond what is standardized in ${widely used library}; we need to hire a cryptographer." In that sense, we need to instill a better anti-crypto ethic.