Couple of things.
For most players, very possible that the position they played in HS will not necessarily be the position they play on a college team. The coach is recruiting a player for a reason, that reason just may be that he has the ability to play on that team, but the coach may have other plans along the way. During the recruiting process, this is good to discuss with the coach. If a player's goal is strictly for one position, it most likely is not going to happen. A good example I know of is a player on son's team, outfielder with a great bat but a stronger loose arm. He ended his college career by being drafted by the Yankees as a pitcher and an ERA and strike out leader at the cape. At first, he wasn't happy, his folks weren't happy, but the coach saw his bigger role as a pitcher and where he could HELP the team the most. That's the key work HELP. Though some are just happy to make the roster, others aren't happy with the coaches decision. IMO, they probably might not be happy with the next coach's decisions either. In this case, I think that the parents (very nice people) added to the frustration, but after seeing how successful their son was, everything changed. They also learned to become pitcher's parents.
As a parent of a college pitcher, I had no problems with him starting off slow. Weekend starters might average 100+ innings per season. My son was not happy either relieving, his coach's philosophy is that you learn it all, early, and for him it worked out well and he enjoyed for a few years wearing all hats, he enjoyed the role of "go to guy". Yeah, he most likely could have gone to another school and been the friday night guy for 3 years, what for, more work on his arm? In my experience, I'd rather he be able to learn in differnt roles, rather than thrown into the fire. An inning here and an inning there, is how you learn. The total college experience is more important than just the playing experience, JMO.
Sometimes things happen, injuries, short players from the draft, that forces the coach to use freshman early. It's early, things change, where you begin the season may or may not be where you end your season.
For position players, most likely if you can hit, you will get the job above eveyone else, that's just the way it is, you do not have to be the best at your position. That's how I saw it happen on son's team, if you hit, you played evey game and learned your position by trail and error.
I agree that parents must keep their comments to themselves regarding playing time or position, this only fuels the fire, because most of the time the coach has a reason why the player sees limited playing time.