I feel that the role of a JV coach is to develop skills which will enable those JV players to become varsity players. If the JV wins most of their games, that is a bonus. If the JV loses all their games, but the players are being well coached and becoming better players, then the goal is being accomplished. You have an extremely important role as a JV coach. You are developing future varsity players.
The level of each school district's youth program will ultimately determine how well the incoming players skills have been developed. I hold clinics for all our youth coaches, hold summer clinics for every age group of players, give individual lessons to players as young as 8 years old, and help coach the Jr. High summer rec ball teams. This takes a lot of time but it is the only way to make sure the players reach your program with the fundamental skills of running, throwing, catching, bunting, hitting, pitching and are mentally intelligent players. Not developing these skills properly at younger ages makes the job of a JV and Varsity coach much harder. For example, instead of being able to work on offensive or defensive strategy, you spend most your time teaching players how to throw and catch. This can put your program 1-2 years behind others. Instead of underclassman having a chance to help your varsity squad, it take 1-2 years for them to develop. Understandably, not all high school coaches are respected by their community so this makes the job of developing a youth program even more difficult. However, if you can do things to earn that respect, young players and coaches will flock to you for advice.
As the head coach, I do not micro-manage my JV squad. I am blessed to have a great JV coaching staff. However, as the head coach I do have the right to give my opinion to those coaches and players and to bring up a player from JV if I feel she is needed for a certain role. Any JV coach who would tell me to pick my team and leave would have no place in our program. Our JV coaches not only help develop the JV squad, they also work with our varsity players. All our players respect them as much as any varsity coach because the players know these coaches have the knowledge to teach.
It is extremely important for the JV/Varsity coaches and players to feel as though they are one unit. We practice together as often as possible; have inter-squad scrimmages; when possible we attend each others games; we make sure the varsity players stay in contact with JV players at school. We believe as a team that we are only as good as the last player on JV. This is why our varsity players take time out to help others. If you have an attitude that your JV is nothing more than a way to get a couple future players developed, I believe that is all you will probably get. If you believe that every player, no matter how bad, may at some point in the future play a role on varsity, then I believe you will develop a much stronger overall team.