i am sorry but other than "we have one team with one coach to watch 100 kids" this is baby fascist nonsense. the football team would probably have the opposite response to having hundreds of kids show up. they would start frosh A and B and soph A and B teams and hire new coaches. they would be running practices during school periods to stagger kids' presence if the numbers got too big. they would not set about trying to figure out ways to cut the interest in the sport back down to "the kids they really want for varsity. who they think they can win" my god.
and let's be real, those teams are outliers. most HS teams have like 10-20 kids showing up for XC and a spot here and there open to varsity TF.
i knew a couple guys who couldn't regularly make our district winning junior high team who went on to be regional-qualifying seniors who had D1 level stuff. what they had in common is even when they weren't going to meets they were at practice M-F every day, working their tookus off, and it eventually paid off.
i also think in practical terms the "7 kids per XC team" or "3 per TF event" limits do a lot of the work for you. if you don't make enough meets you ask yourself is it worth it. but then my experience sometimes it pays off. i don't see the point in being arbitrary for the sake of showing how tough you are, as that mediocre frosh you cut may have been a growth spurt from being your best miler or 110H guy.
i also feel like this garbage trades in the weak weak weak suggestion that the state champions or qualifiers i ran with were somehow lessened if we let the 10 min mile kid even on the team. those two kids aren't usually even on the same team -- one will be the varsity star and the other the JV/frosh mascot. and no serious person feels like the varsity competition of the best kids is lessened if a single slow senior has to finish a race slower. they are wowed by the fastest kids.