But if you want to talk muscle and brain power... I can't use modern DSLRs because I don't seem to have either the muscle or brain power to press all of those buttons and scroll through all of those menus. Or maybe I just can't be bothered by trying to control a camera that way.
That's just it. I have only to look at two settings and the viewfinder/groundglass. Anything more is needless clutter to me.