I've been gaming since EQ release and even EQ has not died. Damn thing has 18 expansions now I believe.
I can also give WoW as a prime example. They've got one of the worst communities and have since Cata was released. WotLK had a lot of asses, but Cata REALLY brought it out, yet the only reason they lost subs was because of how poor Pandaland was designed at the start, yet it still sits at about 8mil subscribers.
As for leveling up a new account, I don't have to level a new account to know the issues. I've invited my own friends to try League and even when I first started back when Diana was released, there was toxicity issues. A good majority of these issues are caused by the fact that it's a FtP game. When any game becomes popular and free, it tends to attract the worst kinds of people, usually ones who don't even speak the proper English.
During my own first level up was a huge issue with Latin Americans. Nowadays I usually see people speaking in Asian languages. I've yet to see anyone speaking in English writing versions of Asian languages do anything but bitch just like back in the day, anyone who spoke Spanish at champ select usually ended up cussing the entire game when some one would die, when they would die, when they were losing, or the game simply wasn't going perfect.
Honestly, it won't be the death of a game to have a toxic community until a new game comes into play for people to jump at. With HotS coming in and already having eSports teams and having college goers do 'Dorm Matches', it wouldn't surprise me if the overflow of toxicity dies down to invade another game. That's usually how it goes. Toxic players move from game to game, blaming the communities for their own failures. Smite is already growing in toxicity and before it was a 'idgaf' kinda game like League was when it first came out.~