My bad... WWJS = What Would Jesus Say, so I'm asking
WWPS... What Would Picard Say.
I mean those discussions about the prime directive and non-interference in alien cultures were frequent and heavy-handed, and kind of spelled out what Starfleet was 'supposed' to do.
Not that that ended up happening in many cases.
Well I think in at least one case Picard would have gone along with the PD because it was supposed to be a greater, if nonsensical good, but he wouldn't have liked it (I think in the case I am thinking of they found a way around it). But even when carried to such extremes, it is not the same as actively helping your opponent on their way to oblivion. Nor do recent discussions make it seem reasonable that the Narada could have passed through the black hole as it would have to fly around a singularity that was already inside the ship. Well, according to the commentary, which agrees with what we see and what makes sense. The visuals may have been more ambiguous but we and nuKirk know how and where the black hole was ignited.
Also going from "offering" help to execution does seem morally "unusual" to me especially when he had the safety of his own ship to consider which could have been an out. It looked like they just wanted to have Kirk and Co at least contribute to destroying the Narada and didn't understand how questionable the situation they constructed was.
Now in the case at hand, here's a guy (Nero) who exterminated an entire world and wants to go down with his ship. He tersely gets granted his wish by a cocky Kirk and bereaved Spock and goes out in a hail of gunfire, so to speak.
I don't see the issue with what is typical or not in terms of Starfleet. Even a seasoned Kirk once said of the Klingons, "Let them die..."
By "cocky Kirk" you are suggesting he is not ready to command a star ship and therefore not representative of Starfleet behaviour? Problem is, Starfleet don't agree.
Anyway, the Romulan commander in "Balance of Terror", didn't receive the same treatment from Prime Kirk (granted he was a bit more diplomatic), despite the fact that his only excuse was "following orders". Nero was at least deranged to some degree.
Moreover Prime Kirk's attitude towards the Klingons was understandable given his personal circumstances (which is unlikely to be the Starfleet line anyway), but he didn't actually let them die, much less abet their demise. That is all the difference in the world (if not the multi-verse) to me.
By the way, Nero didn't really want to go down with his ship. He just didn't want help from Kirk. Had a Romulan ship been handy however ... .