HoTS is no different than it is here. The games are merely shorter by design. But believe me when I tell you that you can get just as frustrated and angry playing HoTS as you do playing League of Legend. For me, sometimes, it is even more so.
I take a very Captain Kirk view on losing: "I don't like to lose." Yes, it happens. Losing is inevitable in team competition. If I try very hard not to lose and do anyway, I did not try hard enough. That may or not be the case. That's simply how I feel about it. This was something I was told all my life. "If you lose, try harder next time." Yet when that next time comes and you try as hard as you can and still lose, what's next? I have limits. I'm not The One and cannot bend reality around me to help make the impossible possible.
The problem is perception. In most cases, a person will look at another player's win / loss ratio and, if they see more losses than wins, they'll say "That player is no good." The general perception is that a really good player won't lose. Occasionally, a smart person will look beyond a win / loss record. But this is not a common thing. This is one of the problems I've encountered trying to get ahead in HoTS. The majority of the player base look at two things to determine how good you are: your win / loss record and the MMR. As I've already stated, win / loss is just the tip of the iceberg. But HoTS MMR is based on a system that Blizzard neither records (publically,) or displays. HoTS's MMR is put out by a 3rd party website and it compiles an MMR for you based on the games you played that either you or other players have uploaded to the site. So, if I play fifty games and only ten of them get uploaded, that's the data the site goes by. It's not accurate. A baseball player's hitting average takes in to account every time the player goes up to bat. You cannot just ignore twenty games. But that's what this site does. And players hail that site as gospel when deciding how good someone is even though it's dead wrong. But trying to force that logic on people is futile. "Yer bad" is all you'll get.
If you can lose and enjoy it, more power to you, man. To me, losing is a sign that I'm not good enough and have to do more to win. But even Micheal Jordan cannot win a basketball game alone. Someone's got to pass him the ball. Someone has to get that rebound while Jordan moves in to position to score again. And while I try really hard not to blame other people (because it's seen as petty and whiney,) it's tough to watch someone charge head in to a 3 on 1 fight and be decimated again and again and say that player is not helping the team with their actions. Oh, it's easy to not type it out. But think it? That's another issue.