In current lore, Skyrim IS more than just bland ice and snow, this I know is true, and there is no reason why Skyrim CAN'T be an interesting place to explore. I just don't have any confidence that the people who turned the jungles of Cyrodiil into Generic Fantasy Fake Medieval Europe Land could make Skyrim an interesting place to explore. That, and I just don't like Nords all that much, and I'd much rather explore Elseweyr or Black Marsh, mostly, the reason I don't want the next game to be in Skyrim is not due to anything I have against Skyrim but because I have my own preferences on where the next game should be set.
Also, in Bloodmoon, we already had a chance to explore a bit of Nordic culture, while this look into it was nothing compared to what we'd get in a game set in Skyrim, it did give us a bit of a taste of it, and that's more than can be said for other races that are not Dunmer in that game, not to mention Bruma seems to give us a good representation of what a Nordic city might look like, Khajiit, Argonians, or even Altmer or Bosmer did not receive anything like that. Of course, since I do not like elves, I don't want the next game to be set in Summerset Isle or Valenwood.
Everyone wants to see different provinces. Satisfying solution is to have them all, if they only have sensible main quests. It's also waste of resources not to include them. Tamriel is 1 solid land so it cuts out Akaviri and others as necessary episodes.
The problem is, if Bethesda tried to do all provinces, at least with current technology, they would probably end up being far too small and lacking in detail, just look at how people complained about Oblivion being too small, and imagine the outrage if Bethesda had to put all of Tamriel on the map when they can't make it at least on the same scale as Oblivion (so that the map's Cyrodiil would be the same size as in Oblivion.) although you can see into the other provinces in Oblivion, you can only see as far as the view distance allows, and you don't see details like roads, ruins, towns and such, if Bethesda had to let you explore those provinces, the additional details that would need to be added would certainly do a lot to expand the production budget and increase production time, not to mention to keep such a game plausible, Bethesda would need to add a lot of new models and textures so that every province could look as it should.