Robbing a bank could be successful too, without getting caught or risking your life. The shady businesses on the streets guarantee a profit. If one sells drugs on the street, he's guaranteed to make money. The case is not the same with gambling. You may or may not.
In fact, I do not even think the two should be compared by any means. I would say your statement is even more logically flawed when comparing those two things and I can totally understand what betwrong is trying to imply here. He never said gambling is not risky, but certainly not the riskiest which I would not think someone in their sane mind would want to rob a bank or do some crazy illegal stuff and think they would in the long run easily get away with it.
It is impossible and that is even more risky than gambling. In the long run though, when young people are in their early age exposed to things like this, which includes gambling, the making of decisions without ending up on the wrong side is somehow inevitable.