Summary

With the adoption of the new issue view, the ADF becomes the right way to create content for issues, however, while you create content through the rest API and it fails due to a wrong syntax, then only a generic error is prompted that doesn't provide enough information to identify the mistake. 

 Jira should be more explicit and give more details about the problem, for example:

"custom_field_12345 encountered ADF error @ offset 156: node type not allowed".

The AtlasKit is not widely used for all users and it is not implemented for a variety of languages.