Dunmer are xenophobic, racist pricks. Imperials, while corrupt and two-faced, at least give a degree of autonomy (sometimes it is high) to its provinces. Dunmer, on the other hand, would like to enslave everyone. They treat other races like shi* and Morrowind was the last province to abolish slavery (with much opposition - that's part of so-called "tradition", after all). Most of them believed in Tribunal (i.e. traitors who made themselves godlike for quite a while) and were guided by the Temple, an oppressive institution in itself. They despise necromancy, yet they summon ghosts and skeletons to guard their tombs.
Spoiler I'm just wondering what those buffoons think now, when their province has been conquered by the ARGONIANS and Vvardenfell has been turned into Wasteland because of Baar Dau, which was the source of their pride. After all, their saviour "saved" the ancient city from destruction. Just a delay, I think. WHERE ARE THEIR GODS NOW?! They are certainly not with the rest of Dunmer freezing their asses off in Solstheim.
Altmer are terrible, too. In fact, they are similar to Dunmer in many ways, even if they won't admit it. Although xenophobic and haughty, they seem to get back to their senses, with young Altmer protesting against birth control etc. For me, they are just a more "civilised" version of the Dunmer.