The studies showing Dvorak superiority apparently were never compared with qwerty users going through similar training, and when they did, the advantage disappeared.
Apparently, we do better if we train.
I'm self taught through online games like StarCraft and don't use the home row - my hands settle in a different location, I use the edges of the keyboard for positioning (mostly through peripheral vision rather than touch), and I use my elbows and shoulders in addition to my wrists to move across the keyboard. Don't have to stretch or twist my fingers and wrists into awkward positions that cause strain, never had the issues others describe, and so far no hint I'll develop them.
They hate it for the same reason they hate recycling and climate change. It's a very visible and popular example of markets not being perfect and needing regulation to perform better.
It's highly likely that your source was in economics rather than ergonomics.
Is the original paper that kicked it off, I think there was a few follow ups.
This wiki page has a snippet from a site talking about it that is no longer online:
https://wiki.c2.com/?TheFableOfTheKeys
http://www.mwbrooks.com/dvorak/dissent.html
edit to add:
https://reason.com/1996/06/01/typing-errors/
Vs