I think one of the fundamental reasons why people often exhibit bad sportsmanship is because they haven't put Magic in its right place. Magic is a game.
When a lot of us started playing Vintage, we were teenagers, or in our early 20's. Even though the cards were significantly cheaper then, I know that (for me) the money was a lot harder to come by. Buying a Mox in 2003 or 2004 was tougher for me than buying a Mox would be today, and I think that's true for a lot of the people who played back then.
The crux of this was that even though we were working, we weren't making all that much money, and many of us were looking for a way to make a few extra dollars here or there; it would help expand our collections, maybe it meant we weren't strapped for cash that week. In order to buy my first set of Beta Moxen, I had to work out a deal with a store owner who was willing to take $100 a week for me for several months. I couldn't afford to buy them otherwise. When you're in your early 20's, potentially still in college, you're not going to be making the kind of money that leaves much disposable income.
I picked up a lot of shifts working security (graveyard shifts) to be able to afford my first set of power. When I finished my first set of Moxen, I carried them all with me, in toploaders, for a week or so. I would lay them out as I sat in my security booth; I felt pride in having put a set of Moxen together (an aside; Alpha and Beta power will always, always, always look nicer, but Unlimited power will always be special in its own way, as it was what we could afford, and there's a magic in your first piece of power that a gem mint Beta Black Lotus will never have).
Many years later, upon meeting Raffaele Forino, he made a point of noting that if money was an issue for him, he'd just work instead. If you're showing up at tournaments with an expectation of making money, just how much money are you really going to make? Pro-rate that out over the number of hours spent, and then think about how much you'd make if you just spent that time working instead. And if you're not working a job where you can make the kind of money to afford the things that you want, what are you doing to ensure that this is no longer the case in the future? How much do you really want the cards? Are you willing to work a second job for them? Are you willing to make sacrifices in other areas of your life for them? I was broke for the better part of two weeks after I picked up a Mox Ruby from Dave Kaplan back in 2002 (I couldn't have put $20 together). Worth it. The barrier to entry now is obscenely high, and I wish they'd axe the Reserve List, but it's still possible to slowly buy in. If it's important enough to you to do it, you'll do it. And if it's not, it's not; the key is knowing where you stand.
I bring all of this up because it's so easy to look at the prize support, not really have all your priorities in order, go out, play in an event, and maybe take those losses a little harder because your house isn't in order. I don't think I was ever a 'bad sportsman', but I definitely beat myself up harder after losses than I should have back then, when the money was so tight. I could see how that would cause people to lash out, transfer some of that anger that they may subconsciously feel about things, and direct it at whomever they have sitting across from them. It sucks for everybody involved.
Before Magic was anything else, before it was a collectible, before it was about the art, before it was about the tournaments, before it was anything else, it was a game. A game. A recreation that you enjoy in your spare time, and that you play because you enjoy the game itself. Visna Harris is one of the best men I know, and he's having a good time no matter what his record is. He's kind, generous to a fault, and always laughing as he's trying to win with whatever crazy concoction he brought that day. I love this and I wish that everyone was like this.
One of the things that has always bothered me was about players discussing the E.V. of tournaments, and pushing tournament organizers to commit more support than could be reasonably expected. When we all flew to GenCon to play in Vintage Champs, there was the flight, hotel, food, entry costs, etc. Who came out 'ahead' in that calculation? The winner, and...? The tournament isn't being framed the right way by those who would view it through those parameters. The tournament is a vacation. Yeah, I want to win. Yeah, I'm going to test, I'm going to play my best, and I'm going to try to drive you into the ground (while never sacrificing my integrity), but this is a game. The person sitting across from me is a gift, I owe the tournament organizer, judges, and assorted staff my thanks for putting together an event that gives me a chance to play a game I love, I am lucky to be able to play that game and I should be thankful for that. I shouldn't be showing up with an expectation of the 'value' I can gain on the day, because the value I do gain from it all has nothing to do with money, even when I win.
Human beings are complex, and when you show up anywhere, you're carrying things with you. There are always other aspects that factor into how we react to the people around us, how we feel, etc. We don't always react the way that we should. When we don't , we should acknowledge it, own it, apologize for it, and try to be better. Reading about Brian becoming better is heartening. The primary emotion that we should all derive from this game is gratitude.