The guy was arrogant, yes. But he had the numbers to support him. Furthermore, the death rate of mothers at the hospital where they did all the autopsies was so horrible and so well known that soon-to-give-birth mothers would fake illness near the other hospital in town just so they wouldn't need to give birth over there. (Don't have the reference handy, I've read it in several places).
But the general response was not "well, that's a theory worth testing". It was "This guy is crazy. Gentlemen do not pass disease". I have read no record of an alternative theory of the high mortality rate that anyone else had advanced - one might have existed, and was lost in the myst of time. But I find it just as likely that there were, in fact, no competing theories.
I have unfortunately witnessed a modern day case applying to a much smaller population. Not much has changed. I know a doctor who has literally (and provably) saved at least ten lives based on his understanding of a disease, which he cannot support with statistics yet - his statistics keep improving with every case, but still not at the publishable 0.05 threshold. And this is an extremely rare disease (in the order of 1/1,000,000), so it might take 10 more years until he has a rigorous proof. (Alas, giving more details would basically be naming him and myself, which I do not wish to do)
His theory is a lot easier to accept than the prevailing theory about said disease, except that accepting it proves incompetence of many in the field, including editors of medical journals -- which, indeed, is the case, but those cases are dismissed as occasional random misses rather than the systemic incompetence that it is.
It is possible this doctor will retire before they have enough evidence to publish their results. And despite the amazing results so far, when I went for a second opinion after talking to this doctor, 4 others told me that he is making a mouse out of a molehill, and that it's almost impossible that he is right. Luckilly, imaging results proved he was right, and another life was saved. And you know what? Of those 4, only two realized they need some introspection, and the other two dismissed this as a "lucky guess".
The more things change, the more they stay the same.
P.S: Said doctor is extremely humble, and communicates very clearly.