You are wrong on practically every account:
> Joe Developer sees this advice and decides not to write crypto software.
False. Moe Manager stomps his foot and makes Joe Developer wire together "something good enough", regardless of Joe's qualifications. Since neither Joe nor Moe are able to tell how good a crypto system is, they invariably end up with something in the awful-to-kludge spectrum. Both Moe and Joe need to be repeatedly reminded that they don't know enough about this non trivial problem to make good enough calls.
> That's unambiguously bad, because the software industry thrives on failing a lot until a good solution is found.
"Unambiguosly bad" is a thought stopper, a rhetoric trick. This just means that since you don't like any of the options made available to you by reality (like... paying big bucks to a real expert), self deception is preferable.
Now, the fact that our software industry thrives on failure... I am ashamed to say that this just means our industry is really good at externalizing the consequences of our own incompetence to the customers. This is all good and fun, until real lives are on the line. Crypto is one of those cases, so it is one of those lines you don't cross.
> There needs to be a way to develop crypto software that falls in a land of, "Don't use this yet, but maybe someday after we're done testing it, you can start using it and be secure" rather than "nope, just scrap the whole thing".
Are you familiar with the term "Security by Design"? It is one of those pesky realities I was talking about. It basically says that you cannot create a product giving no concern to security, sprinkle some crypto fairy dust on top of it, and magically turn it into a secure product. If you try to do that, you'll end up with a product with broken security.
Which is not all that bad in practice. There are lots of useful products that we all are better of having in insecure form than not having at all. But if the whole point of product X is to be "Y, but done securely" there is no redeeming feature that can save X from the axe.