What do u think about players staying 2 years out of high school, rather than just 1?

I mean I like it if they changed it to 2 years out of high school to then enter the NBA and here is why. YOu dont get many LeBron's or Carmelo's who just come in the NBA and play extremely well as a rookie. YOu look at lately, especially this year, who are the rookies that are playing the best? It is the players that spent more than 1 year in college (besides Jennings who actually played pro in Europe) but Ty Lawson, DeJaun BLair, Blake Griffin(hasnt played but will do very well) Stephen Curry, Jonny FLynn, Taj Gibson, Tyler Hansbrough etc Tyreke Evans is basically the only 1 and done player right now who is playing well but he his also playing over 40 minutes and has the green light to shoot and actually isnt shooting a good % at all. Think about this though, it would defenitely improve college ball and will improve the NBA too. Do you guys think they should keep it the way it is, or change it to 2 years out of high school?