Would you still buy a game if the publisher treats its European customers like total garbage, or you'd cling to your pride and ignore it, despite wanting to play it once?

I'd ignore it most of the time, in all honesty. Sure, I can still spit on the publisher for the awful attitude, but as narrow-sighted or non-caring this may sound, I care more about the game ultimately than to miss out on a game I'm interested in because of factors like this. I still understand folks who rather boycott a game in a case like this and they tend to have a lot of point about it as well, but as for me, I usually don't feel hesitant to buy a game with a bad publisher. I care more about what the programmers/artists/designers/etc. created than to be held back by the incompetent nature of those who are responsible to deliver the product. There are barely any developers/publishers out there who I feel completely devoted to anyway, so I don't feel any sort of "betrayal towards myself" when I buy a game that I find interesting from a developer/publisher with questionable business practices. That's why I'm saying jokingly that I'm "boycotting" some developers/publishers by only being interested in a handful of their games, and not caring the slightest about the rest.