People can do good things and bad things but I highly disagree that every successful business progress because they do underhand tactics and abuse people to the point of committing crimes. Not all businessman or company owner are crooked, others often offers charity works to the community as way of paying back to the people who help them grow.
Besides, if your argument about people getting successful because they do gambling, I think you are wrong to think that gambling is a criminal act. In many country, gambling is legal, even establishing gambling platform and establishment is encouraged because it helps in the nation's growth and development.
All these so called dark secret are just rumors unless proven by proofs.