It's always funny how people get upset by concessions. Now I agree that doing so AFTER the game is over is bad form for several reasons but it seems many are just against the idea period. If you want to concede to your opponent then "OFF WITH YOUR HEAD!" seems to be the popular form because why would anyone do that except to manipulate game results. Maybe you can forbid concessions but where does that stop? Am I cheating if I "accidentally" fly all of my ships off the board and give my opponent a win that way? It is? So how about if I fly so poorly and happen to land on asteroids and such right in front of his ships making the game easy for him? I guess that is still cheating too huh? Now I guess I people seem to have no problems with me forgetting to do various things like take actions and if I fail to "remind" my opponent that shooting at a ship with a Rebel Captive produces stress that is all my fault. Heaven forbid if I happen to ask my opponent if he was skipping some trigger he could/should be taking advantage of.
If this is how tournament are run...