I think it's important to not confuse "dogma" with "development best practices," a lack of which is one of the problems that is hurting software development. People go off and do their own versions of password hashing because they don't know what's the best practice or think they'r e being safe.

Is it important that you know why brcypyt is a best practice? Yes. I understand that it (tunably) is slow and uses a random salt, which I also know is a best practice for hashing passwords. Is doing repetitive sha1s going to work well enough? Probably, but I don't know enough about cryptography to know fo sure. So when smart people say, "use bcrypt," I do just that.

Programming is too big of a topic for everyone to understand everything about what they're using. We have to trust others.