Why the hell should he have to 'like airplanes'?
Aviation is just another public transport system - no more, no less. It is no different from running a bus or train company.
O'leary is just a businessman who is very good at his primary purpose - make profits for his company. If there were more senior exec's in the aviation industry who were like him, rather than those with this 'romance of flying' tosh, then we may not be in the **** we are in now.