I also agree with your opinion. The lozenge perspective maybe have had a trend for some time with these people, but it could have changed. Just like how modern art has so many different perspectives. Hence why the other scholars may have not agreed with McDermotts hypothesis. Paleolithic art probably had different artist just like the modern world. Each artist would have had there own style. This sort of art may have 'trended' with the people for a while before they changed the trend. It's human nature to change what they like and don't like. Either way its still fascinating and beautiful.