Re cheating on AoR
Maybe 'ignored' wasn't the most accurate word (I've got no desire to denigrate the efforts of live GMs), or maybe my experience (on KN) just differed from yours - I think a lot of people will remember how it was essentially just accepted that certain players could 'teleport' etc. But my point was simply that I don't think there's any value in looking to AoR and whether they considered NB acceptable or not.
Re value of NB
Agreed that the impact of those other factors is at least as great (and much more so, imo) as that of NB; this in itself seems to have no bearing at all though on whether or not NB is acceptable. You say that "there's certainly more than enough more impactful conditions...", but don't finish the sentence -- more than enough for what? To negate the issue of NB? I don't think that follows.
No one reasonable is saying that there's some perfect, godly script which can replace all player autonomy -- if that were the case, I imagine there'd be pretty much unanimous opposition to the addon. But the much less absurd reasons people have actually given (including in this thread) for opposing it still remain.
I wouldn't call it 'discrimination', but yep agreed that hostility/aggression and calling people who use NB bad, or cheaters (which is just false since it was never blocked/banned), is obviously unhelpful to say the least. It does seem that the negative impact on players caused by the shock/suddenness of the change could've been reduced by warning about the change in advance; whether the team had a good reason not to do that or just didn't really think, I don't know. Regardless, that's an issue of implementation (that the team will learn from, I guess, if they feel they need to), rather than the quality and value of the change itself.
Re slippery slope:
I'm not seeing any slippery slope myself. I used the phrase 'pvp automation' at the end of my post but maybe should've made it clear throughout - I think most would agree (and would've assumed) that it's automation affecting PvP that people have a problem with, so not, for example, MiracleGrow. I realise you could then argue about automation in PvE (say, dungeons), but I think that'd be clutching at straws and a little disingenuous -- the 'PvP automation' issue really doesn't seem that nuanced or difficult to understand. So far, from what I've seen, no one has actually comprehensively addressed that fundamental issue, which is telling in itself since it seems to be the primary basis on which people oppose NB. BuffHead, like all other supposedly similar examples given in this thread, fails on this basic question of automated decision-making. If there are other addons that provide similar functionality, I'm genuinely curious to know, but I get the impression that this (apparently erroneous) argument is just being thrown up as a smokescreen.
Re pushing it into the shadows:
I don't feel I know enough about this to have a meaningful discussion, but I'd say it sounds like a valid concern, and if the basic intention behind the disabling of NB can't be implemented in a solid, robust way, then it would probably be better (imo) to revert the change until it can.