The interesting thing about the whole dynamic is that we are looking at things with 20/20 hindsight. We know it isn't until 2014 that an openly gay guy actually gets selected by a pro NFL team. I think that perspective is part of why Mark likes to write historical fiction, taking into account the cultural milieu of the period and working around the cultural boundaries of that time. It sure has set up a tense dynamic for Will and Zach and as many have noted it appears to doom their long-term prospects.
However, as Kit points out, they are both young and will probably change quite a bit as they mature. Even a mature fifteen year is a quite different person at twenty-five....And while to them ten years is an eternity, it will pass faster than they expect.