This is among my least favorite tropes in scifi. Sure, the alt-universe/transporter copy/lab clone version of our character is functionally the same, but it's not really the person we've been following all this time. And worse, it's never brought up again, like it's understood that killing them was an emotional cheap shot and shouldn't have happened.
The only time it's really worked well, IMO, is when Beerfest did it.
It's not harassment, it's protocol. Starfleet has seen enough evil doppelgangers ranging from transporter accidents to mirror universes that there is a policy that forbids them from working for Starfleet. Fake-Kim is not a Starfleet officer, but an auxiliary officer like Neelix and Seven, which is why he is never promoted.
A situation that he was placed in by Janeway, just so she wouldn't have to promote him and the other Janeway doesn't have to either. Yes it was to save baby Naomi Wildman, but that's besides the point.
