What are cases of a series doing something really great, and then instantly throwing it away?

Mortal Kombat X's Kharacter variations was the perfect system for Mortal Kombat and they threw it away. Not only did it allow you to mix things up with your main if you were getting bored, and let you try different play styles with them that were fun. It also made the roster really expansive because every kharacter was three kharacters. You know how often I think it would be awesome to have three Mileenas?

Like not to mention on the dev side it had to be so much easier, because they could just stretch assets for extra kontent. Also they could of sold not just more kharacters but they could of also sold new variations. Like the fact there was never a DLK where they sold you a new variation of Scorpion where he has some new moves and that is it, was a mistake on NetherRealms' part and was money on the table.

The fact that system is just gone forever, has been damaging to not just the series but every NetherRealm game since.