Andy,
One sense it makes is that the amount of "revs" a person has is one of the many important factors is determining how a ball will work for them, how to drill it, and how to get the proper surface. The ball and the lane do not care where he is in the "pecking" order of revs. However, it can make a big difference in what ball is picked and how it is prepared for him to use.
It almost seems as if you're implying it's an honor to be a tweener instead of a stroker. My opinion, FWIW, is that it's not a bad thing nor a good thing; it just is.
Redefining medium "revs", as you seem to be approaching it, is often, in the world of statistics (Some statistician, please correct me if I'm wrong; it's been a LOONG time.), is what is termed the median. That's the number at which 50% (correctly, 49.99999999999%) are above that rev number and 50% (correctly, 49.999999%) are below that number.
That would draw an interesting picture, but wouldn't have much meaning in the world of bowling balls or lane oil.
However, an Average is a very different thing than the median. Average is more of what's the lowest "normal" rev rate and what's the highest. Halfway in between is average or medium revs. (See something called the "Bell Curve".) I know it seems it's all a way of playing with numbers, BUT, we play with them until we can get meaningful results that can be used purposefully. Right now, the "median" is only intellectually interesting, not practically interesting. Average is of at least one practical use.
This is only one piece of one point of view.