Actually, a few years ago I've heard BA
did the same to a couple caught joining the Mile High club aboard their plane.
ban people for periods of time, or even life, if they feel it's warranted.
However, I do not believe that smokers pose a safety risk, aboard an aircraft full of inflammable materials. Smoking is a nuisance, and that's why it's banned on every European airline, as far as I know. Passengers should be fined, or even banned for a year. But to claim they pose a safety risk and ban them for life, while banning people comitting "criminal damage" and "causing a disturbance" only get banned for a year, that's illogical. I'd rather sit next to a chimney-breath than some drunk hooligan.
On the "banning Ryanair" thing: Ryanair is easily the best shorthaul airline in Europe (if not the world) today. They offer magnificient value for money, safety, and punctuality. I prefer those qualities to "customer service", especially if it means, in most cases, that I'd have to cough up 100-200% more. In fact, it recently was cheaper for me to fly CWL
than to take the train.