I quite agree. I suspect the opposition to MWI lay less with the science and more with the very idea, the concept thereof. I mean, here we are, the human animal unable to comprehend the vastness of our own universe, our own reality, and then someone’s trying to tell us that this universe is effectively only a unimaginably-minuscule part of the whole?
It’s as we’re a race of amoebas (amoebae?) some of whom postulate the existence of a universe, while the others look at us and wiggle their pseudopods in frustration at the very idea i.e. “This soup is all the existence there is!”