That's not really respawning. It repopulates everything at once and it seems very artificial. You are on an island and have killed everything that moves; where did the new things suddenly come from?
I consider the way repopulating works in G1+2 to be just about perfectly balanced between gameplay and realism - from gameplay standpoint, completely absent repopulation would be boring and more dynamic (chapter transition independent) repopulation would be annoying, given the games´ scope.
Partial repopulation upon chapter transitions gives the games some sense of dynamics and realism without compromising gameplay in one of the two above mentioned ways.
Also, it does not repopulate everything. You´re correct there are no real "respawns", only additional spawns, and a lot of these is story related (at least in G2).
Argument that you´re on island and thus respawns don´t make sense is weird.
Both games, G2 especially, maintain a certain degree of abstraction/reduction in their world design and their scale and within these parameters, the context of in-game(s) "realism", "respawns" are perfectly acceptable and consistent in my opinion.
Pretty much every game requires players to accept this sort of limitations, Skyrim included. You have to adhere to in-game realism, otherwise you´d be constantly wondering how comes that such a supposedly major city as Solitude has only 80 or so citizens, for example. Take a stroll through Rift woods, you´ll be hearing birds chirping constantly, but there will be none to be seen - another abstraction.
Etc.
Taking these limitations into account, G1+2´s repopulation scheme feels less artificial than Skyrim´s to me. Skyrim´s wildlife respawns are ok from the in-game realism perspective to me, but the respawns in camps or dungeons are not.
It feels like the world is full of invisible enemy groups which just wait for you to clear a place for them and after a while it starts to feel like there´s a lot more of outlaws than normal citizens.
And all respawns are the same general type of enemies, the difference is only in their strength, based on your character level. The game is big so this kind of limitation is understandable, but it doesn´t make it feel any less artificial.
Also, if you combine exploration with questing (radiant questing especially), you´ll be dealing with these dungeon/camp respawns often and that, at least for me, is boring. I thought the radiant stuff was supposed to predominantly send you to locations you haven´t "cleared" yet, but this very likely does not work in the game. Maybe it works within the radiant quest system itself, but in my game it didn´t seem to take into account "clearing" locations on my own (without a quest) or via a non-radiant quest.
Since the general respawn period seems to be much longer than in Oblivion, it´s definitely an improvement, but overall I´ve found it quite a bit more verisimilitude-breaking than in G1+2 (I actually didn´t find it verisimilitude-breaking at all in those games).
That said, considering the Skyrim´s scope, I think the implementation is good overall. Hopefully few of the truly glaring issues will be addressed via patches - some of the specific cases which I´ve noticed that need to be taken out of respawn include the named vampire mini-boss or the note in Labyrinthian, for example.