Sort of like the Babaloynian-infused number 360 as a represention of circular rotation, it seems to work as a good base system.
My concern, like with Strava, is the obsession over them. Strava obsession invokes the Tuesday All-American. Speed ratings is a slightly different obsession.
In the other threads, the kids and dweebs use them matter of factly and I think that needs to be pointed out as a problem. I think it should be a "fun way" to size up a performance but not taken as a matter of fact because it isn't a fact.
You say you are concerned, and this is a problem, but what is the problem? It is just a ranking system to compare things that are otherwise hard to compare. Is it any different than the MileSplit or Dyestat rankings? Aren't they also a "..fun way to size up a performance but not taken as a matter of fact because it isn't a fact"?
So what is an actual factual comparison? If the answer is you can't factually compare cross country, that is a pretty weak answer, but lets go with that. What would be a factually accurate way to compare times? Just track times? So a 4:08 mile is factually better than a 4:09 mile? What if the 4:08 was run in perfect weather in heavy competition in California, and the 4:09 was run solo in 30 MPH winds in Oklahoma? Would somebody who really is trying to compare times think the 4:08 is factually better? If so, it is a fact that is misleading you, and therefore of limited use. The way speed ratings are done, at least the course and the weather is somewhat taken into account, and therefore in some ways is a better factual comparison than even track times.
So what is admissible as fact? By a strict definition, no comparison of times run in different environments is. So we go with the best approximation we have right now. In track, people just use times, even though it is obviously flawed, because it is good, quick approximation. In XC, they use speed ratings, with the same plusses and minuses.
He told you he is concerned that.people are obsessed over them. I am concerned that people are obsessed over being thin because it causes eating disorders. We should always be concerned when somebody is obsessed over something.