Do you think high school busts fail because of their work ethic?

i disagreed with stern that you must be 19 to enter the league, i feel its the kid coming out of high schools choice if he wants to come in the league, if you see the great players that have come out of high school such as kevin garnett, kobe, lebron and yes t-mac its because we hear so much about their work ethic, with flops like kwame and eddie griffin i always hear they dont work hard enough so i think there shouldn't be an age limit for entering the league let those kids who work hard succeed and let those who dont work hard play in europe, please i want your opinions