.ngo/.ong doesn't require official non-profit status, it just (in that dimension, there are requirements in other dimensions) requires an organization to be non-profit-focussed.

I don't understand the difference. You mean like a C-Corp might technically qualify if they happen to be focused on the public interest and not generating profits?

As a global TLD it surely makes more sense to look at what an organization actually does than just blindly go by what the local tax authority thinks.