She doesn't have much in the way of jealousy and hatred towards Kitana though, not in the current timeline; that's an old timeline thing and said jealousy and envy came about as they grew up together.Each to their own, but I actually thought it greatly stunted, even changed her character.
A huge part of her identity was that she was so different and obviously non-human. Remember she is a Frankenstein monster basically. By giving her more human features, they are reducing part of the characters identity and almost removing all the historical lore surrounding her jealously turned hatred to her "real" sister and how they relate to each other.
So in mind mind it not only looked terrible, it also completely gutted her identity and destroyed decades of story. Plus tradition is a thing. I liked her they way she was, the way she always was, and I do not see that a need for change was warranted or even executed well when it happened.
Mortal Kombat (2011) completely changed and removed that, and instead made Mileena new "born," immature, and insane. By the time of the Mortal Kombat X comics, she had actually grown up and matured (mentally) significantly.
Looking at said comics, and then the game itself, she never mentions Kitana once (Story mode and lore, Versus intros are not established canon), and even in Mortal Kombat (2011), she only talks to her once directly when she first awakens, and then mentions her briefly to Jade before they fight. That's it.
The Kitana/Mileena dynamic was 100% changed years before her retconned mouth ever came to be, so in terms of decades of story, the real question should be: how did Raiden sending his memories back in time alter things 10,000 years ago so Mileena was not created then!?!?! As fun and enjoyable as Mortal Kombat (2011)'s Story Mode is, there's lots of things that simply make no sense having been changed by Raiden's memories being sent back alone.
Aesthetically, yes, to each their own of course.