Neutral Evil win conditions are silly. It's something that we've never fully changed over the years, as the current win condition hasn't caused much controversy. However, Kleptomaniac and other assorted non-Warlock NEs have been used in games on-and-off since early 2016, so a change is overdue.
I am reminded of SFM9 when Cow was lynched at the end as Witch and lost while the game was almost entirely guaranteed for mafia to win. The best counterargument I can think of (aside from the ToS legacy) is that, since the role is neutral, they need to rely on themselves to win. While this is fine with Executioner, we have changed NE to be anti-town roles with more flexibility and power than mafia traitors.
Currently we compensate Witch with a 1-shot shield, but Kleptomaniac- a weaker role- has to rely on a protective or a night immune to die for protection. I think it's be better to give both of them the Warlock's ability to win, even in death.
Since the Witch's shield would be somewhat redundant, it could be changed the version I used in 14D:
Spoiler:
This protects it from any scum attacks, but allows town kiling roles to bypass the shield. In 14D, the Witch counterclaimed the Doctor on D1, resulting in the death of a powerful town PR at the very start. While this was strategically a poor decision, (the Vigilante shot them the next night) this example showcases how a change like this allows for the witch to play more aggressively while not punishing the Vigilante for making the correct shot.