Just wanted to provide some insight on these points from I've seen from a collegiate perspective and as a high school coach (recently "retired" from the MW Board, have become active in the SAC, and have talked to ~30 teams throughout the country about how they run things, and coached HS Lacrosse for 4 years).
On the point of skiers/athletes deciding not to pursue their chosen sport in college, a lot of it stems from three major factors:
#1-- Burnout and change in scenery. From what ive seen, especially as a varsity sport coach, many kids finish their senior year and are just ready to stop playing their sport. Its not unusual to want a change in your life after doing something for so long. Some of the best lacrosse players i grew up with played from 6yo through senior year of high school, they just had their fill of the sport and moved on after graduating.
#2 -- Kids like to form their identities during their freshman/sophomore years of college, and often times that means they try new things and drop what they've done in the past. If kids only associate skiing with "boring" AWSA tournaments with their parents, of course they're gonna want to do something different. The trick solving this would be to find a way to create a more team oriented environment for younger skiers. (Show Ski teams thrive on having groups of 5-12yo and 13-17yos being in the same acts and associating skiing with each other rather than with their parents)
#3 -- There's also a number of people who go into freshman year wanting to (rightly) focus on school for a bit, and by the time they're comfortable adjusting the season is already over or they've made friends elsewhere and don't want to miss any events with them.
As far as ski hierarchy goes, from what ive seen in the Midwest teams follow a few different approaches depending on their ski situations:
1) "Fun" teams with limited practice time -- A few teams I know follow a fairly strict whoever gets to the lake first, skis first. This is pretty great for ego-less skiing and getting more people in the water, however many of these teams typically don't compete as well.
2) "Comeptitive" teams with limited practice time -- typically are trying to win tournaments and qualify for nationals. This situation will have more hierarchy, and A team skiers will get priority, and if there's time, B team will ski too! Typically B team will still ski, but their sets might be shorter during the season. -- This is how my first year went, I took 10 maybe 15 sets (including tournaments) from August-October. I loved it, but didn't actually ski much. I can absolutely see how an experienced skier who's on B Team might not see the value in being on a team with this situation
3) Competitive team with unlimited practice -- usually a pretty rare setup, but this is where B Team skiers thrive. A team skiers still get priority, but the lack of urgency in lake time means that skiers are free to come and go as they can, which means new skiers get many more opportunities to ski and are invited out more because teams usually need to ski in groups of three. These B team skiers tend to ski more, ski better, and build up stronger relationships with their teammates as the practice environment is much less structured.
Typically in all cases though, whoever shows up first will get on the water first, if someone shows up late, they're getting the last set of A team skiers, and if they show up when B-Teamers are skiing, they're likely getting pushed to the very end of the order