I know there's plenty of threads about why one ES game is better than the other. I just want to know how the fanbase is split up. In general, do the fans of morrowind and oblivion stick together and dislike skyrim? Or does each game have it's own following and dislike the other games?

As for me, I love all 5 games for all individual reasons. I'm a fan more of the elder scrolls lore behind the game

every tes game release creates a new fanbase, that's because the games are so different. some people prefer the first game they played and sticks to that one, and some follow all the game in the serie like they are holy things. i'm not sure if Morrowind fans and Oblivion fans are band together, they have always been at war

Every fan base stands on their own it seems. Of course there are instance when they are agreeing with each other.

I love each of the last three games the way you might love three very different children for their interesting and wonderful idiosyncracies.

That's a great way to put it

While there can be distinct differences between subgroups of ES fans, they aren't as divided as the fans of the Fallout Series.

With the fallout series, you have two overall large groups, Old Blood and New Blood.

Old Blood enjoy the first two games, and (usually) see anything beyond them as a stain on the Fallout name (justified or not.) They also tend to view the New Blood as ruining the series, causing the new owners of the series to trample over established lore and what everything means in the series.

New Blood enjoys the recent games (FO3, FO:NV,) and typically view Old Blood as stuck up and fixated on the past games, unable or unwilling to look past "minor" changes made in the recent games, especially if its a natural extrapolation based on ideas detailed in FO2.

As with all groups, you do tend to have some overlap, and the Old Bloods you see on these forums are typically on the moderate end of the scale. Of note, FO:NV seems to be the only Fallout game that both Old and New Blood enjoy.

Buuuut, as I said before, the Elder Scrolls community doesn't have that kind of a relationship between groups. Some hate fans of some games, others like them all. By and large, though, we do tend to play well together.

That's very similiar to TES fanbase actually, the old bloods are the morrowind fans while the new bloods are the Skyrim and Oblivion fans (Mainly Skyrim though).

I do think the fanbase is divided between the games, and the different groups don't like each other. The most hate comes from the "real" gamers towards the "casual" gamers, IMO. And the problem goes further than dislike, there is a glaring lack of respect for one another.

Yep, and the Oblivion fans are the one that is stuck in the middle hated by both Morrowind and Skyrim fans.

Each game attracts certain population.
Morrowin attracts misunderstood hermits. A unique nerd representation.
Oblivion is a magnet for American Pie/Godzila population.
And Skyrim is sublimation of both, a try for community to gather on a single new place. Does it work? I think so. Is it a good thing? I dont know.

Of course there are going to be divides. If you play Daggerfall, then Morrowind, then Skyrim, they're clearly very different games with different design goals. It's easy to see why someone who loved Daggerfall may not have liked Morrowind... or why someone who loved Morrowind may not have liked Skyrim.

Divides are also inevitable when any form of entertainment (such as video games or music) goes from having a fairly niche audience to being a mainstream hit - as the case has been with TES.

...That isn't to say people can't love all of the games in the series. Lots do.