Should players make the jump from HS to the NBA

This has been an ongoing argument for a few years now, so in this column, I'll examine, year-by-year, the success of players that have jumped from high school straight to the NBA. I'm an advocate of an age limit. Let me explain a few reasons why:

The Shaun Livingston reason: Would Shaun Livingston's body have fallen apart in college? Probably (this would have been an outstanding reason to not draft him). But think about this; the best way for Livingston to have had his body ready for the NBA would have been strength and resistance training. Livingston is about 6'7" and tiny (he appears to weigh about 160 pounds). A college coach would have put him on a weight program and had him in the gym with the goal of getting bigger and stronger while maintaining his quickness. AND all this would have been going on while he was playing a much less taxing 30-35 game schedule.
The Gerald Green reason: Gerald Green is one of the strongest athletes I've seen on a basketball court. Gerald Green is also one of the most confused players I've seen on a basketball court. His team's game plan in HS was to let Gerald do whatever he wanted until he got tired. When Gerald got to the NBA he had no concept of how to play the game, how to run plays, how to do much of anything within a team concept really. Let's understand this: NBA coaches don't teach players how to play basketball. NBA coaches put theit players into positions where they will succeed, and ask them to leave their comfort zones a little bit at a time in order to improve them as players. With some better instruction at the college level, Gerald Green would most likely have been ready to play the NBA game at age 20, rather than still floundering after 4 years as a pro.
Here's the big one, and this is the one my friends frown when hearing:
The LeBron James reason: LeBron James was great in his rookie year, a force really, but just imagine if he had been in a group of his peers in a college or other development setting prior to his entrance into the NBA. We would have seen a LeBron that knew he was the best player on his team, knew that all the offense should start with him and knew that he didn't have to defer to his teammates unless he wanted to do so. He would have taken over his team in year one, and he would have been right to do so.

Having made those points I'll group the first few years together (1995-1997), and then start looking at the success of HS players one year at a time. You'll see why the NBA instituted the age limit rule, and why it's not only good for the league, but also for the kids that are coming out of HS.