"The first thing they (athletic administrators) will look for are liability concerns."
I buy that. However, keep in mind that most of the preseason/training practices of many mainstream sports (football, soccer, basketball) are far more demanding than an ultimate tournament. I don't think you're going to convince anyone that ultimate is more dangerous than football because the athletes play more games in day. In my experience, athletic administrators are meticulous about keeping waivers of liability on file for every athlete that might be competing and as a result, liability is rarely an issue with any students registered at any of the schools in a league.
Overuse injuries do occur in ultimate just as they do in most other physically demanding sports. Ask anyone playing college ultimate, even those that played 4 or 5 games/day in high school injury free: You are always fighting some sort of nagging bothersome issue. How many players in Scobel's photos are using ankle tape, or a brace of some kind? The quote given to me from Colin Gottleib: "you're never quite above 90%." I understand the instinct of the veterans to protect the youth, but I don't think this is the way to do it. The nature of the game is such that players that love the game and intend to keep playing for years to come will deal with nagging overuse injuries sooner or later. No one wants to head off to college excited to play ultimate only to be hit with a rude wake up call that his/her body can't handle the demands of the game at the higher level. Preparing them for increased demands will keep more young players playing in the long term—better for the player who gets to keep playing his/her favorite game, and better for the game itself.
Soccer has the luxury of paying their top players staggering amounts of money for their ability to fill stadiums with paying fans. When they play a tournament, they do not have the issue of school or a day job away from which they must take time. As a result, they can play 1 match every other day over the course of 3 weeks until a champion is crowned.
Ultimate players do have the issue of school and jobs. A full 2 days is usually the most time any large group of players can hope to have in which to play through pools, elimination play and then crown a winner. It is impossible to complete a thorough and fair set of competition in that time frame with games limited to 2 per day. The proposal of making the juniors' championships a format more akin to that of the world championships seems like a good idea, but it falls short. One of the biggest reasons for the incredibly high level of play at the College and Club championship tournaments is the tough preseason. Once these teams reach the end of the season, 2-3 games/day is much easier than what the brutal preseason offered. The juniors' teams would be left without that training at their disposal and as a result, they would be less prepared for a longer event and a peaking opponent. I worry more about much more devastating career ending injuries in this situation: one in which the demand is greater than the level of preparation.
Is it wise to taper down the number of games allowable for 8th grade and younger? Absolutely. I think US soccer is on to something with staggering their recommendations based on age. However, given the level of skill and athleticism juniors players are currently achieving, I don't believe we should put that restriction on high school players.
One of the many wonderful things about the World Cup is that ANYONE from each nation can play if he/she is good enough. Pele made his world cup debut at age 17. Lionel Nessi at a similar age. There is a similar quality in the club series. Again, pointing at Stubbs, Lindsley, Castine and Rehder.
Consider the repercussions of slapping the playing restriction on these juniors' leagues. What would keep these players interested in them? As it is, Rehder probably gets very little out of it himself, but with him playing, the league as whole benefits tremendously because of his ability to elevate the level of play. I imagine there are several young players that participate in a Seattle youth league that are looking forward to the chance to cover him and see what they can do. Keeping the top players in the league is in the best interest of everyone involved, but I don't see the league holding on to these top players with a playing restriction.
I will buy into the idea that we should not ask a juniors' team to play 5 games in a day. But that is where I draw the line. Based on my time spent as a high school player and what I've seen come out of high school since, I believe we should let them play up to 4 games (particularly in the preseason) so that we can continue to see their level of play rise. Give them all a bye during the day and keep them well hydrated, but let them play. You'll keep the top players in their respective leagues and have all players more prepared to continue their ultimate careers.