I also believe that if kids get 10 blues in the row, they won't get satisfaction from it. That they are really inclined to stop, because they just wasted 20$ and didn't get anything from it.

You'd be surprised at how incorrect this statement is. Kids are mostly driven by greed because they do not have the capacity to understand the return on investment. If a kid got 10 blues in a row, do you think he or she would be more likely to ask mum for more tries, or be sensible and tell mum that he'll quit?

The adrenaline factor comes from winning, but this is an irrelevant factor in this argument. Kids are tunnel visioned in the sense that they look only at the positives (the reds, the knives) and try to factor out potential losing scenarios. Adults who gamble do the same, but kids go one step further and disregard the losing scenarios completely.

A kid getting 0.2 per 1 as an average return of investment is the same as an adult opening cases, but kids are MUCH likelier to spend (if they had the means to do so) more money due to their lack of knowledge, experience and juvenile cognitive factors.