I understand that the people who have been doing this way longer than me feel heahbutting the glass and fist pounding the glass after a drain is part of the game, but why? Just because people have always done it? And if it's always been acceptable, what happens if there's no beer seal on the game or if someone gets a concussion from bashing their head into the game? Wouldn't it be easier to just do away with these than keep them around? Like an unsportsmanlike penalty. I get my example may be extreme and rare, but they technically could happen.
If you have to take your frustration out on a game, just walk over to the game next to the one you're playing and rage shake that one. I saw @pinwizj do this at PAPA and it was not only hilarious, it does zero harm to the game or player.