Hearthstone is an obvious counter point to this.
http://us.battle.net/hearthstone/en/blog/13665270
This tournament is created by blizzard which has an obvious incentive but there are plenty of other large hearthstone tournaments with healthy audiences.
In practice the high level players who you see on tournaments on Twitch are all playing with all cards (or max level heroes) available. In Magic: The Gathering this costs $xx,xxx (for modern) or $x,xxx (for standard). In League of Legends, this costs an unskippable grind, but you can pay to make the grind shorter. In Hearthstone, this costs about $800.
Notably, some competitive games do not have this property. In DotA, you can play every hero at full power without paying money or doing a forced grind. In Ultra Street Fighter 4, you can play every character at full power after buying the game for $40 or something.
Edit: anyway, the original comment was about "purely intellectual" esports. I think this means "0 execution" esports? Like, turn-based games where whenever you try to do something, you succeed in doing it, or at least succeed with a known probability instead of a probability based on a test of dexterity. So Hearthstone is definitely that, and "but Hearthstone has cards with rarities" is a red herring.
Why do we expect that playing a fake version of the hero against other fake heroes is better training for playing the real game than just playing the real game? What if the player picks up habits that are only good when the opponent cannot use the correct runes, spells, and masteries? In our Street Fighter example, people could learn to do things that Chun could punish with SA2 but not with SA1, and they would get away with them until their summoners reached the max level.
What if the player is an experienced LoL player who moved to a different continent, or a genre savvy player, or a LoL player whose previous account was banned? These players can't really benefit from the forced grind, even if it has any benefits.