Most service / retail industries train on the job. Now this is difficult if your entire business is open just 23 or so times a year.
Would they bring in their staff on a non match day, teach them to pour pints (which are then waste) etc and would still have to pay them for their time. - No...
There is only a limited time that staff can serve and limited space in which to have kiosks, so what do you propose? - employing a large number of staff that means everyone gets served even if they are paid say £6 per hour and only needed for 15 minutes and end up costing the club more in wages...
You expect them to employ professional (restaurant quality) staff to serve in the kiosks for approximately 23 games a year and will only be needed for an hour and a half before the match, 15 minutes at half time and then a couple of hours after the match?
Who would bother with that as it...