Irwin was a guy who would smile to your face then stab you in the back, for money. There were plenty of people that helped him become a billionaire that he totally screwed. Irwin did care about perceptions though, so he kept Qualcomm a good place to work, as far as public perception went.
Paul is just a good time guy, born with a silver spoon, just wants to milk the business his daddy gave him, with no real hunger to excel.