There are MANY rewards in game that is Hard to get and not just a mindless casual farming as you say it yet its not limited exclusive. Hard to get =/= Exclusive,limited.
Also those exclusives DOES hurt everyone that cant get it and Cant work towards it because it got removed when for them they are one of the best looking stuff in the game..
For example the season 19 armor set... like are you kidding me ? How many people got pissed ? ALLOT.