My opinion: I think “actual Buddhists” are the rarest beings in the entire universe.
The number of devas seem to be a mere fraction of the number of human beings.
The number of true Buddhists seem to be probably a fraction of the number of devas.
That seems to be my overall impression.
The numbers in the poll seem to relatively accurately capture how many beings in the world “call themselves Buddhist” or “identify as Buddhist” or “born into a family where their parents identify as Buddhist.”
I think it would be a lot more difficult to accurately determine the number “true Buddhists.”
Interesting 
like what?
Agreed.
The Buddha said that one who understands the Dhamma is rare.
Another good point 
is there any way to poll those who have already attained Parinibbana?
Similarly, is there any way to poll the devas?
@SarathW1 you mentioned free inquiry - I think that was what was being referred to.
The Buddha said that both wrong view and right view should be understood. How can one make a judgment on a view that one isn’t even aware of and hasn’t carefully considered?
So yes, nazism should be fully inquired into just like everything else in the universe - the false, harmful parts of it should be rejected while the true, beneficial parts (no matter how little) should be accepted.
Good points.
I agree
I agree. A “true Buddhist” is not made by birth the same way a true Brahmin is not. The Buddha seemed pretty clear that birth status counts - aside for say external social, conventional, and ceremonial worldly benefits - for nothing.
Harmful bhikkhus who hold false views and commit harmful actions should, if upon investigation warranted, be criticized and perhaps even expelled from the Sangha and not be associated with.
