WoW Ruined itself. Ghostcrawler had little to do with that.
Not gonna comment on League atm, but Remember that Balance in an MMORPG is not done the same way it is done in a MOBA.
There's a lot more Depth to stuff like WoW's balance. You have a million different factors weighing in on it
Classes, Racial bonuses, Party perks, enchantments, jobs, specializations, mastery trees, pets, auras, Status effects, Weapon stats etc etc
Meanwhile, LoL, while having less technical Depth as a WoW balance system, has its own issues due to inherent differences in the games, the largest being Items
Every character in LoL has access to every single Item (Give or take a few special exceptions). This presents a few problems. In WoW this is easier to balance because Items can be Class Restricted. You probably wouldn't see a Druid attempting to slash Deathwing apart with an Infinity Edge, for example.
In League the only "Class Restricted" Items are

I'm probably just repeating myself over and over at this point, but basically, The two games work completely differently. I have no Idea how this actually relates with most anything here.
I am tired.