So much hate for a mean bitchy character....
I don't see it as a reboot, soft or otherwise. It's simply a progression. Leah was a bitch and we didn't like her for it; she came around. Sara was a bitch and we hated her for it; she's still coming around, but we accept that she's getting better. Even our hippy chick was a bitch, and I sort of didn't much like her either, but she's coming around as well.
This one was captured and left for dead. She's had a long time for the guilt over something she may have caused to make the situation of the island what it is. Probably the only thing she thought about was breaking out and fixing what she did. She isn't evil, she is simply obsessed with correcting a mistake. Okay, may a bit more than obsessed... But she isn't evil, as such. No villain out to fix the ills of the world is truly evil in their own eyes; and mostly they can't understand why others can't see that they are trying to make things better. Thanos didn't see himself as evil; he was trying to save the universe from millennia of death, and war as too many beings fought over it's limited resources.
Frankly, I figure our hero stood down himself because he respects Leah's wishes. And I think it would be extremely evil to have those girls some of you are so ready to have kill the bitch do so without trying to find a better solution. Alice would definitely cook her over a fire for Reggie -- but she would never be the same, sweet Alice again.
Give it time, the lady has some issues she needs to work through. I'm sure our crew will help her out with a forceful intervention at some point.