Bit of a pointless question IMO. Aviation is regulated by qualification. That is each qualification comes with privilages. If the regulator says your qualifications allow you to instruct than you are an instructor. If they don't then you are not. This encompasses far more than the just holding a flight isntructor rating. TRI's for example do not have to have a flight instructor rating but are clearly instructors.
Chuck I still do not understand why you have such a hate on for pilots who have a flight instructor rating. It is the system they operate in that is the problem not the fact they hold the rating. IMO the antidote to poor flight training practices is articulating a better way, not blaming the person.