They release toons through this method to give them exclusivity so people who can spend have an advantage, which they should get as they support the game.
They do have other release methods for toons.
This method give 'new content' for us to play and then offers the grind we all know and love. If you don't like them just don't play them and you can start your grind from 0 like you want.
The events also allow us to unlock them and gear them up as we see fit from day 1, which means we get TB value and can prep the toon if we feel we are going to use them later in the game.
Moved to correct sub forum.