Ring stored WiFi credentials in plaintext on their video doorbells -- would you say it requires a cryptographer, a network specialist and an embedded device expert to know that was a terrible move for a home security device you can walk up and physically rip off the outside of someone's house?

IoT manufacturers don't have to contract Linus Torvald to review their code, but it's entirely reasonable to expect IoT manufacturers to use existing best practices to secure these products.