The two are not incompatible. Sure, most people are better off using off-the-shelf crypto or chemistry instead of rolling their own.
But as a society, we stand to benefit from educating people. Someone has to actually build the off-the-shelf crypto, right? So if strictly everybody is told "nah, don't roll your own", who's going to advance the field?
My point is that we should facilitate people understanding things. Sure, this may push some people to figure "meh, I know everything, let me just roll my own" and proceed to build something buggy. But that happens anyway.
> Yes people need to know "how to make smart crypto decisions", but when you are dealing with sysadmins or other end-users, I put it to you that they could not care less about the mathematical theory, what they really want/need to know is "what settings should I be using with $insert_name_of_crypto_library in my config file".
I'm a sysadmin and very much like to know how the things I deploy and manage work, so I can make decisions about things. That doesn't mean I'm out here writing my own OS or anything.
Also, I think being educated allows people to be less susceptible to snake-oil salesmen and the like.
A good current-day example is the debate about cryptography backdoors. Maybe if more people understood how things worked, they wouldn't keep parroting the line of "nothing to hide [from the government]", because they'd understand that bad guys are extremely likely to have that very same access.