Steve Scott, your logic is flawed. Why would Ritz be saying all the training he has ever done was wrong? He was trying to show the massive potential Brent Vaughn has. A guy that runs 8:45 off of 35 miles a week is obviously a great talent. He's not saying every experienced runner should be running 35 miles a week. Finally, the whole saving yourself so you can improve in college idea is stupid the way most people use it. Sure you don't want to burn out by running intervals or races 5 days a week in high school. Those who do well in high school on low mileage then show a lot of improvement in college with higer mileage are talented runners. Gradual progression is key. People talk about all these runners that don't improve by leaps and bounds in college. Let's take two runners. They both run 14:30 their senior year in college. One guy built up to 60 miles a week in high school and ran 15:25. The other guy never ran more than 25 miles a week and ran 17:00. The fact that the 17 minute high school runner drops 2 1/2 minutes in college while the other drops less than a minute isn't an indication lower mileage is better and the higher mileage runner burned out. Who knows, maybe the low mileage high school runner could have run 14:10 if he'd put in more miles in high school.
Generally, I think there are truths on both ends. A lot of kids that come out for xc have never run before, and don't have body types that are going to support high mileage. Obviously, each runner should start off at a level that is right for their talent and experience and then gradually progress up.