It's common in most sports, difference being in most sports they have agents and managers and player associations that are all over the young guys when they step out of line.
I grew up in Canada and by 13 we had to wear suits to games, mandatory, if you didn't you didn't play, didn't matter if you were the next Gretzky. It wasn't a matter of tradition it was showing respect to those who came before you, to the people that came to watch you, and who would later on be paying your wage, the money that would earn you a living, provide for your familiy, the image you presented was something that the next group of kids would see.
When I was a kid, making it for me was getting to wear that suit, I would see guys in the NHL arriving to games dressed like that and that's all I wanted. I didn't know how much shit got said on the ice, there was no twitter and all that crap, I just wanted to be a the guy showing up to a game dressed up it was a huge day for me when I got that suit and got to do that for the first time.
People are reticent about dota becoming too professional, and even at 37 I can appreciate a guy like slacks and such in the sport, the shit talk in games or on twitter is difficult for me, the ego and such, it's on the players to tone it down and set an example for the next batch of kids coming up, something to aspire to beyond simply winning this or that and it'll happen. Lots of these guys are still finding success at a later age, late 20's and so forth, who have spent enough time in the real world now to appreicate a little pomp and circumstance. The group of kids that are 10 or so, that'll be coming up, I bet things will be different. As more and more pros age and approach the fans and their fellow competitors with a little more respect publicly, the next group of kids growing up watching will respond in kind.
Sumails a little shit most of the time, but so are most kids his age, my son is 15 and some of the shit he says I just want to smack him. Eventually he'll get a job and work around mature people and he'll learn from that, cause he sure as shit won't listen to me, just like I didn't listen to my old man. Sumail the more he spends around older successful players, the better his attitude will be and the more he'll find people will respect him, and he'll feed off that more than anything else.