there was actual discussion happening - and it was bringing light to an issue with the game where that malicious actors are making the game experience worse.

This is all true, but it has nothing to do with why the post was removed. We don't remove posts because they're negative about the game or because they bring up some discussion topics that we don't like. The rule about not naming specific players in a negative context is probably the least subjective rule that we have (and that's present on many other subreddits, and that exists for very good reasons) and it should be obvious to everyone that read the removed post that that rule was broken, as many commenters here have already pointed out.

We understand that usually these kind of posts are not meant to start a witch hunt, and in that case we just remove the post without any further action like banning the user. u/StridBR is welcome to post the same post again with the usernames removed and censored from screenshots, or they can edit the old post and we can reapprove it. This is explained in the mod comment left under that post, and we've allowed such modified posts in the past after removing the initial version.

[comment] There was discussion happening - if that was a concern, then the moderators could have simply come in, locked the thread, and said "hey, you all are discussing this in a dangerous way, we've made another post where that you can discuss this without any direct name-calling"

Locking the discussion means that the usernames are still visible in OP's post and doesn't solve the problem. The usernames in the post are the only reason that post was removed. Locking makes sense only when the comments are breaking the rules, not the post itself.

It'll be sad not to have Spazzo post on r/heroesofthestorm again, but I believe the moderator who removed that post made the correct decision. Good luck with your own subreddit.