giving money based on rankings will result in failure. You've got kids chasing points, dodging people, NOT fixing their game which at their age has gaping holes. Why, because fixing your game takes months, years, learning the transition game, retooling serves, hitting bigger 2nd serves will result in double faults, taking more chances on 2nd serve returns/short balls/neutral balls all this will result in more errors. But that's the shots that are needed at the next level.
You can't just punt it over with good topspin and expect to win at the highest levels but I still see this at the futures level. The only US guys who are making a dent in the pro game now are probably Ryan Harrison, Sock, Johnson and it's because they have huge serves with exceptional spin. Please read this guy he knows what he's talking about
Basically the top juniors and college players are giving up 20+ mph and that gives the other player too much time.
I rarely ever see US guys on junior or futures tour with a big enough gun to consistently hold serve against pros. Then they get balls near the service line that they can't consistently punish against top level players (sure they can hit winners, force errors on me/you/lower level guys but not against the top 1% of 1%).
If player development is to continue you need to seek out guys with live arms, who can hit huge serves, penetrating balls(forget about % and consistency you can learn/develop that, you can't go from being a consistent safe guy to having a live arm).