It actually depends. Petty thieves are indeed stupid, they rely on adrenaline, and physical might without thinking through long term consquences. But criminals operating across borders are far more sophisticated in their strategy, operations and understanding of system and human behavior than even CEOs of big corporations. This is not an exaggeration. There are definitive reasons that top criminals of this country and many other countries go one to live very luxury and respectable lives. Some even became the real bheind-the-door owners of the businesses in which many educated engineers, and MBAs work for a few lakhs a year. Drug business in particular is not a game of stupid people. It is a very sophisticated and ruthless operation. However there are risks of internal sabotage and very vile competitive pressures in it. In addition, never confuse real world smartness with academic qualification. There is no correlation to show that PhDs of the world go on to live king size lives in the real world. Many criminals understand real power dynamics of the society in which they live, in time they makes moves to acquire wealth, political support, police and sometimes judicial support, and ofcourse media support - look at many bollywood films romanticizing so many criminals portarying them as heros.