I interpret 210.12 to say that all new dwelling units have to have AFCIs on bedroom branch circuits. Is this correct? Im not sure ive seen this in some new constructions, i.e ive seen just standard breakers installed in panels. Are there exceptions?
There are no exceptions in the NEC. But local codes may take priority, and some local areas might not have adopted the 2005 NEC yet. Your interpretation is correct in any area that has adopted the 2005 NEC without having amended that article by one means or another.
If you are seeing this after the Job is inspected it could be an unscrupulous contractor. Taking AFCI's out after inspections, don't laugh, I've come across these a few times!