How is that a valid justification for reinventing the wheel, and poorly at that? In the end they're having to come around and learn SQL anyway, judging by all the Mongo hate and "why we switched to Postgres" posts I see here, so they gained nothing by avoiding it.
>or even know where you're making the wrong choices.
They could try actually listening to older developers for once and trusting established solutions like PostgreSQL instead of chasing after everything new and shinny that catches their eye.