Because running legal business is a lot harder than running illegal one. With legal business there are laws/regulations and there is competition. When you run d

Because running legal business is a lot harder than running illegal one. With legal business there are laws/regulations and there is competition. When you run drug business and competitor show up you just take a gun and eliminate your competitor (simplifying here of course). Another thing is that you will get respect from a lot people in certain circles and a lot will fear you if you've built successful crime organization. It's a lot harder to get that running pharma business. Why do you think people like Escobar didn't just retire having hundreds millions of dollars? Sometimes its not all about the money in the end game. They do invest in legal businesses to launder money most of the time. Being on top of large criminal organization is intoxicating just like having power is.