As an instructor I would be quite happy to leave a PA28 or C152 with the engine running, doing the same thing with a DR400 would require a bit more thinking about but dong this with a DA40 simply would not happen. However I have been working around propellers for years and have a respect for the dangers and always approach or leave an aircraft from the rear.
The problems start when people who do not appreciate the risks of propellers are unsupervised near live aircraft and people new to flying are not trained properly , after all how often do you hear a student call “clear prop,” and instantly start the engine allowing no time for a person to step away from the aircraft ?
Old gits like me consider propellor awareness as part of airmanship but no doubt the new and politically correct title is now T.E.M.