I am in agreement with Jess and Sunshine and that group of guys on this topic but I wanted to bring another matter to the topic.
Coaching is better now than what it was back in the day, When I was youth bowler I had my Dad teaching me and I had two or three other coaches their every saturday for all the kids in the league and they were willing to share their knowledge with us if we wanted to hear it. or spend time when league was over helping us work on our games if we wanted the help. I know my Dad didn't have anyone helping him out. My ProShop guy said he never had a coach or anything he had to learn on his own when it came to his bowling (He did have instruction when learning how to drill bowling balls and do layouts)
The coaching makes a difference, you can get help out of bad habits faster, and get into good habits easier. The coaching makes you better faster to put it the best way. That maybe leading to some bowlers being able to score better than the other people with the modern gear and conditions.
MainzerPower