That is very true. However, the number of people who are both good software engineers and good cryptographers is very low. Personally, I can't say that I've seen experts being hostile towards those willing to learn the concepts and best practices for cryptography, though. The hostility is usually reserved for those who try to roll their own crypto with ill considered design, no matter how nice their code is (Telegram, etc). But it's possible that I could be entirely out of touch with that.