Gentlemen please - how many times have some of us to say it, it is not the number of pax on a flight it is how much they have paid, i.e. YIELD! The flight may be very well patronised but if most of those havn´t paid too much for the privilege. Now do you get it.
Regarding Krakow - I think I am right in thinking it is the most expensive airport regarding landing fees etc in Poland, one reason Wizz do not operate from there and also why easy pulled the Luton service some time ago and now the Southend route.