Technically, Pablo Escobar was a good businessman.
And there's the rub. Economics are amoral. There's nothing inherent in capitalism that says "We only make money in ways that are legal and ethical". Corruption is part of the nature of the beast. This is why we need to regulate markets.
Make a desirable product illegal, and you've improved the profitability of that product's market, by increasing friction. (As an aside - as Peter Thiel points out, in a free market, profits are driven to zero. That's just math. All profitability is derived from friction, from failure of the free market.) Society winds up attracting the least ethical businesspeople this way - the Pablo Escobars, drawn by the incredible profits that illegal products can generate.
Corruption is a similar problem. Politicians, especially executives, wind up with massive monopoly leverage that can reward or punish businesses. This creates a strong incentive to offer personal financial gain to politicians in exchange for favor. The fact that this is illegal only increases the amount of reward that must be offered.
This makes "businessman" politicians exceedingly dangerous. If they're used to shortchanging ethics in the name of profit already, the power of office is far too potentially profitable to resist.
