I've been scrambling in nike running shoes, solomon low-top hiking shoes, garmont hiking shoes, technical mountaineering boots, etc., etc., etc. On a couple of occasions, even barefoot.
My point is that you wrote "Lot of accidents could be traced to cheap shoes or worn out shoes" yet provide absolutely no backup for it. When asked, you provide examples that are--in your own words--hearsay. In over 20 years of climbing I can't recall ever hearing of an accident due to faulty, failed or inappropriate footwear. Like someone else posted, it seems plausible but an opinion is not empirical evidence.
What is "proper" footwear is, like most equipment choices, highly subjective.