Listen to the early cylinder recordings. The high vocal register was actually preferred THEN. The main reason was The lack of amplification, so the voice could carry and command attention in noisy places (pubs, on board ships, market places, etc.)

This first came to my attention when I heard that during WWI prisoners of war from many lands were recorded speaking and singing by students from Heidelberg University in Germany. Those recordings have only recently been studied and those singers in the main sang in a high register well above their natural voice. This then made me think of Grainger's recordings, particularly of people like Joseph Taylor. Since this time however technology has allowed us other means of amplification and we no longer are forced to sing regularly in noisy places on a regular basis. I am not advocating castration! Though I do know some people who would be happy to practise on me!