Alacienne
Apart from the big hubs like LHR/ Amsterdam etc most regional airports make most of their money from parking/ food and beverage and lastly landing fees. I have never been involved with running airports only building them but Mrs Mac has looked after some regional UK airports at senior management level, and that what she told me when she was doing this around 2012. I do not think anything has changed markedly since then. Indeed they used to strive to get flights to the Canaries due to the advantageous Duty Free allowances on those flights which impacted on the shops profits.
As for drinking onboard, I am sorry but I like my G&T and wine with my meal and would miss it, but we are talking business travel mostly, and even going down to the Med or for a city break, I would not have a drink until lunchtime. I do not understand how you can drink pints at 6.00am !
Cheers
Mr Mac