Many students are already grown up and understand the worth of money. I wont believe that every single student that gamble, gamble all his money and always lose. I believe that many still gamble for fun or use gambling as entertainment activity when they party, and minority, even a tiny amount gamble to earn. But that is their choice. There will always be exception, always be those who are reckless.
What do you think about following? Isnt it better to let students gamble, lose (if they lose) and realize mistakes at their young age, so they would have more time to fix it, find solution, think about addiction. Then make same mistakes when they are old and adults? The size of problems they might get into arent identical. Also students have more time to fed up with gambling, pass anti addiction classes, earn money, they wont into such huge loans as adults.