Comment by brobdingnagians

Closed source is more fun to develop. You get full control over your code, you just have to meet the needs of people who think it is worth enough to pay for it, you can code in whatever eccentric manner you want, and you get to keep the nice wads of cash if it becomes successful. If security is a problem, then the people with wads of cash will leave, but at least there is some incentive there.