uhh, i really don't get your point, dude you're implying that people are making rooms to actively seek red lag/ ping. however restricting the room to Us or EU would actually be counterproductive to that.
also as skill has already said. it's the host's choice of what they wish to accept and not. i know most of the people i play with kinda deal with lag for the sake of playing with friends. so long as it can be bearable.
only thing you can do about it is make your own room.only let people with a certain connection quality join. then watch is no one is able to stay because this game is really unstable with it's connections between two people and how your connection with the host won't be an accurate representation of your connection with everyone else in the room.