The Thalmor want to deactivate all the towers in Tamriel by destroying their stones, destroying mundus, and this will make them become gods or divines again, that does sound quite evil but is it really? What's wrong with wanting to become a God or Divine? Talos did it and he's loved by all of men but when all the elves want to, it's suddenly evil. It's nothing personal against man or beast, I'm sure they won't go into nonexistence if it was to happen, if it does that's a different matter all together.