It could be argued that Vivec, among all the other people who tapped into the heart, is also the lesser of several evils. Although Sotha Sil apparently loved the Dunmer more, isolating himself in a hole and having nothing to do with them is a lousy way to show it. Vivec, the rogue, seems a likable sort of person, god or not. And yes, in every way he's a rotten, cheating, dirty bastard. I can imagine him wearing a "cheat to win" t shirt, a la Eddie Guerrero, if he lived in our world. But he's still got the best personality and supposedly the purest motives of his little clique.
I am very fond of the idea that Sotha Sil was re-shaping the world from his Clockwork City, i believe he did love his people. I dont know how to put it, but i think he was a better person than vivec. After all, he did make the pact with the major Daedra Princes (Ironically, Mournhold was torn to the ground right after by nice little Dagon).
Maybe for some reason the events in Tribunal that led to his death prevented from developing what his true purpose was, and if his research would have brought some grand benefit to Tamriel.
Or maybe the hole point of the character was to remain a question mark and that?s the reason i like him so much. And Sotha Sil wasn?t so detached from the world, otherwise he wouldnt hace come back from Artaeum at all.
But you?re right, he gave in to despair and shut down. Vivec confronted the prospect of losing his divinity, but he did so to his own selfish benefit.
I can never truly decide wether I hate Vivec or i admire him... Maybe both, is this a common feeling??