During film days or were these the crappy Olympus E series digital bodies? It's REALLY hard to change systems. There is a ton of muscle memory with cameras (all their functions/buttons/dials) in particular places. I can see why pros would not want to change. Too easy to miss a shot while fumbling with a control.
My little Olympus OM-D EM5 Mkii has too much customization. (In Aperture priority mode - "Do you want the front or rear dial to control aperture? Do you want aperture to increase or decrease if you turn it clockwise?") If you change modes you can same dial do completely different things; not to mention the 5 custom buttons which be mapped to just about every other function.
Film days. Nikon F2/F3 time.
I like my Nikon D7000, I have it almost figured out after 9 years.