Discriminating againstloud mouth drunks, thats all. Pub owners prefer to keep their customers happy, not watch them all dissapear after a group of stags come through the door.
The loud mothed drunks are the customers. Like I said, it's like having your cake and eating it. Why else would anyone visit Krakow/Budapest/Prague? I don't know people (whether on a stag do or not) who have been refused entry from the latter two places, solely for being a loud-mouthed Brit who just wants to enjoy themselves.
Should Poles be refused the right to use the underground in London? After all, all I want to do is travel to/from work in peace.
Your problems getting served in bars does not imply wholesale discrimination against Brits.
No, the problem most British tourists have getting seved in bars implies wholesale discrimination.
Hope that Helps.