I get that Lemmy's kneejerk reaction is naturally that the big corporation's CEO is wrong and evil (he IS an asshole, at least), but drunk passengers on planes is an actual issue.
I have a couple of close relatives who've worked as air hostesses for Ryanair for years, and they mostly like the job except for summer flights from a specific European island country in which there's a big tradition of drinking a lot and big groups of men doing "guy trips" to my country either for specific football games or for the beaches. These usually involve an almost permanent state of drunkenness, getting into fights with locals, trashing places.
O'Leary's claim about inebriated people being hard to identify is partly bullshit from what my relatives tell me - they say that even when they can notice these groups are already drunk when boarding, Ryanair's staff isn't really comfortable policy wise in preventing them from boarding. Plane staff may refuse them alcohol on board but by then they're usually already in a state of general lack of control. I assume the company doesn't want to strenghten boarding rules in order not to lose these groups as customers, and staff gets shafted in the process. But these people shouldn't be getting this drunk on a plane (or in general).