I think you have to admit that Blizzard's actions in that case were an exception even for blizzard and the rest of the industry doesn't do that.
Yet. A league for a given game needs a plan for its long-term existence should the game's publisher get bought by a holding company unfriendly to the league. Besides, if the exception were to stop being the exception and start being the rule among major video game publishers, how would leagues react? And the Ars Technica article I linked earlier states that Capcom also requires royalties for Street Fighter tournaments.
You possibly could set up your own league but no one will pay any attention to it.
"No one will pay attention to your league" is not the same thing as "you would be sued for even attempting to draw attention to your league."