The Krypt, which they've said they are going to patch to address the grind, is literally predatory practice.
-Intentionally making something terrible & then going "oh sorry, we'll fix it" then putting a bandage on it so it's no longer 'terrible' but just 'bad' going "Hey look, we 'fixed it', we're good guys!" while it's still just frustrating enough to make you spend money.
That's their goal, look like good guys fixing something they intentionally broke, making you spend money on top of the $60/$100 you spent to buy the game (of which the content you are buying w/ these MTX is in the game, so you already paid for it!)
Here's a quick example: 90% of the 'heart' boxes shown on stream, cost /250/ hearts to open, each. You earn... 1 heart per fatality & 2 hearts per brutality. The Krypt, you can occasionally find bodies hanging in the world & they may have 1-2; It's about the same timeframe as a kombat & brutalizing opponent. So you are looking at a 3-5 minute fight for one-two hearts & you need 250... just to open one box & it has /r&om/ contents. You may not even get anything you want, or that is usable for your character.
Now lets throw in 'filler' items. There are 3 sets of icons for your variations, black/gold/red, & there are 30 each, so that's 90 icons. I don't know how many kombat kard borders/backgrounds there are, but icons? If you have Shao Kahn, that's 2250 filler items in your Krypt item pool, on top of like 30 different konsumables for the towers, & like a dozen krafting materials; & those icons? You can get duplicates, so even if you get one from a box, you can still get another.
The kombat in the game? Really nice. The Story? Pretty epic. Actual single player content? Absolutely frustrating, designed to make you spend money to bypass or speed it up. NRS & WB have gone out of their way to try & milk the game cash & are making themselves look like the good guy by saying they're looking into 'fixing' the intentionally terrible grind