"Certainly even among those with the talent not everyone has the temperament, the discipline, the drive and the insanity to attempt a career as a professional singer. "
And that is the more important issue here.
How things might breakdown is interesting.
Another point I think is worthwhile is the fact that the operatic repertoire does not require the most extreme notes for any voice type. Some coloraturas can sing modally one full octave above high C (not flute voice). Some Basses can sing a full octave below their low C2. Nothing calls for those notes other than the Russian tradition of doubling at the octave.
Learning to sing high Cs now I have not lost my low C.
In a sense voice types are limitations of an operatic culture, not so much a true reflection of functional reality.
All by way of saying that it is not black or white. Many factors lead to what may seem like a dearth of dramatic voices.
TS
Be not the slave of your own past. Plunge into the sublime seas, dive deep and swim far, so you shall come back with self-respect, with new power, with an advanced experience that shall explain and overlook the old.
Ralph Waldo Emerson
TS's Blog:
http://tsvocaltech.blogspot.com