Earlier quoted context omitted.
How will people learn if they don't try? The problem is not creating and releasing such applications; the problem is overclaiming their security, or putting early confidence in them. Crypto is hard, we get it. Beginners and non-experts are going to mess it up, we get it. Even experts almost always mess it up, we get it. Still, a good programmer of crypto software (or even just, "wise user of battle-tested crypto libr…
Yeah, my question is what is anyone supposed to do? What if we want something to be secure? Are we supposed to just say "well, I'm never supposed write anything involving crypto"? How do we do things right? Seriously.
When you've done all of that, you'll know that you are abysmally incompetent at cryptography. When you know that, you can start learning how to become good at cryptography. Some people divide learning in four steps: unconscious incompetence (you don't know that you're bad), conscious incompetence, conscious competence and unconscious competence.
Even when you're competent, you will make mistakes, because cryptography is very hard. We've seen how MD5 is now broken, yet still people use it as message authentication ciphers even when it's trivial to perform a length extension attack. But MD5 wasn't always broken. I'm sure it was designed by competent people, but they can't foresee all flaws.
That is why someone who is incompetent at cryptography should not do it.