Question yourself - why do relative many people take effort to learn Dvorak, and a large amount of them state they don't want to go back? Is that because it's an inferior layout? Are all those people fooling themselves? Or could it be that 'qwerty is good enough too', and that a learning curve to another layout is long, and in the beginning, pretty steep?
In this world where people believe in homeopathy, Scientology and other such crap in this world, that argument is not going to find too many takers.