Reach Heaven through violence
I see no reason why you can't have both. Giving moves special properties when used a certain way does not, in any way, directly oppose a combo-heavy system/game. In fact, I'd argue krushing blows would work best in a combo-heavy game. Other games have been doing things like this for years now. Mechanics like a move launching on counter hit, doing DOT if used a specific way, stacking damage on repeat uses, causing variations of stuns, crumples, etc are in plenty of games, especially anime fighters. Mechanics like these add depth to the game and help to differentiate characters from one another.From my POV krushing blows is not a great idea/mechanic. I believe this is one of the reasons the game feels watered down. The flashy combos I was use to watching and doing in MKX got scraped because of this mechanic.
I think krushing blows are a step in the right direction, but the problem is, as they are now, they're shallow, imbalanced, and unevenly distributed amongst the cast. I'd love to see a Mortal Kombat game with long stylish combos where you're also rewarded for clever and precise use of your tools with a variety of unique benefits and effects. Top it off with NRS's exceptional presentation, and I think it'd be something truly great.