There are teachers who don't understand the demands of playing sports, administrators who don't like the attention, coaches from other sports who are jealous, other students who haven't accomplished anything, scouts who are convinced of the talent, siblings and the list goes on and on. So in a sense, the entourage does indeed balance out the cruel world even in high school. College however, changes the dynamic of the entourage and forces players to reform their support system. Girlfriends, agents, coaches and other players all change. In fact, the location frequently changes as well so parents and private coaches can't have the same effect.
College changes everything, but in some ways makes relationships stronger.
It is different for everyone I am sure, but I would have never made it through without the strong support of my family and personal pitching coach. Some guys have strong girlfriends, others have agents and others have strong coaching staffs behind them. I think that all of the dynamics can work, but they all have pitfalls. Agents are only interested in players with big league futures and their support wavers when your numbers go down. Family is strong, but sometimes you need to hear positive talk from someone other than your mom or dad.