Ask other people in this area, not many people will tell you different. I'm not saying he's ridiculous about it but, a 7 should be running racks consistently, if not they should not be 7's. When there are7's out there who run sets, somebody who only runs 2 or 3 a session is a 6. He raise our 2 middle of states. She won a match was his reason. She won 2-1, one of those games her opponent scratched the 8. The innings were 11,12,13.
Not all 7's are created equal. You're going to have a larger margin of skill at the top level than you are in the other levels, just based on the fact there is no higher a person can go. You can't say "when there are 7s that run sets" everyone who doesn't shouldn't be a 7.
4s, 5s, and 6s will seem much more balanced because if they play worse or better they can go down or up. A 7 however (if you're talking 8 ball) has nowhere to go if they play better than other 7s.
The same thing happens in 9 ball. You have 9s that can spot other 9s two balls, again because the better playing 9 has nowhere to go.
Anytime you have something based on a bell curve you are going to have people that shoot better or worse than average, yet still stay in that bracket. One cannot simply say "because the best of the best do it, everyone else should."
Same thing happens in all sports/games. When you look at the NFL, a handful of players stand out among the rest. Based on your idea, the rest of the NFL shouldn't be allowed to be professional football players because the best of them are so much better.