What's the point of the Nerevarine if the whole province get's obliterated about 50 years later?
Lets review the Nerevearine:
He was sent by the
Empire. By destroying House Dagoth and the new Akulakhan, he didn't just save Morrowind, he also saved the
Empire.
Who else suffered from the Nerevearine? Vivec, who always protected Morrowind, lost his powers thus not being able to protect those he loved from Daedra and the Moon.
With fall of Tribunal, the Dunmer had no more gods. So they are confused: some are still optimistic that this is all a lie, some are returning to Daedra worship and many are turning to the official fate of the
Empire.
The great houses also suffered: Redoran was destroyed by Daedra, Indoril are being eaten by King Helseth, ally of the
Empire and Dres has probably been destroyed by Argonian Invasion.
And lets not forget Dagoth Ur, who while being twisted and evil, still wanted to do what he thinks is the best for Morrowind.
Who profited? The Ashlanders, like Vrenir said. Helseth, ally of the
Empire profited. Azura got her revenge (don't believe her claims that she loved the dunmer: she is a Daedra no matter what) and Empire used the situation to assert their beliefs into the Dunmer,
And where was Nerevearine when Morrowind was facing the direst moments of its history? Left for a vacation to Akavir. Well, isn't he a great hero?
So in conclusion, Nerevearine's actions only brought chaos and destruction to traditions of Dunmer (and obviously the destruction to Morrowind itself). The ones who profited where the "enemies" of the traditional Dunmer, especially the Empire. And quite frankly, this seems to have been intended since the devs were making story of MW.
St. Veloth lead them to become the Chimer, away from the Nine (Eight at the time)
Wait, did the Altmer worship the 8 Divines back then? I am not really sure if they worship the Nine now either...