But grinding for the mastery tokens is hard enough in the first place, why make them cost up to a little less than 4000 BE with little-no compensation for how hard it is to get it in the first place. It's like making adding scoops of ice cream onto your cookie-skillet cost $1.00 extra per-scoop. I'm already paying more than enough for this cookie and for it to have 2 scoops of vanilla ice-cream on top of it and for you to make a $10 profit, why on earth are you making me pay for the ice cream to be on it in the first place.
In this case, the grinding for tokens is the base cost of the cookie skillet, and the be mastery costs are the extra scoops of ice-cream
Sure, they're not mandatory, but why wouldn't I want them and still be able to have enough money for chicken tendies (the rest of the champions in league of legends) as my main meal?