I am serious, document a JSON interface with what, English? Are you serious?

JSON has no way to describe in machine readable way what to expect, instead you have to read a document then go hand code the interface in your language of choice.

WSDL and SOAP is not complicated, and I have implemented my own SOAP stack. Then again everyone now days everyone thinks relational databases are complicated.

If you you have tools that implement it for you then there is no excuse.