If you have not played u19 cricket, than you and me are no one to be talking about their habits.
U19 cricket is raw form of cricket where boys are selected based of u19 performance. Sena countries often tell their teams to go out and enjoy the tournament and matches. Dont care or worry too much about winning the tournament, as the main goal is to develop and mature as cricketers and to become professional cricketers (meaning earn from it as a profession).
I have nothing bad to say about the indian u19, and i hope those young kids do win. Because what matters is how they develop and how they compete in international cricket.
Akbar Ali won it for bangladesh, Azeem Ghuman lead pakistan to the finals. But at the end those guys never developed.
Winning or losing an u19 tournament does not determine habits. Its just a group of kids that get some limelight and are than developed after this tournament.
Take Suryavanshi for example, guy threw his wicket away in a very important game here. But i wouldnt bash him cause i would like to see how Indian management will develop this guy and what he ends up becoming inn the next 3 years.