Maybe I'm poorly remembering my early EU, but it wasn't exactly a "and the heroes lived happily ever after" story either. They got, what, 5 years before Thrawn showed up? Then Luke starts the Academy on Yavin IV, has a student decide to murder a bunch of people, and then gets stuck in a weird force coma with Exar Kun. That's not including stuff I've forgotten or the arrival of the Vong which murderized a good chunk of the galaxy (I think - I had dropped out by then).
It wasn't exactly a happy universe.
It also didn't give us Luke Force-Haunting his Nephew, which better be a thing, Disney. It better.
Let's see how much I remember:
The DAY AFTER the Battle of Endor, Luke leads a Rebellion/New Republic Fleet from an invasion from a race that sucked the force out of people to fuel their technology.
Couple years in, there was the Rogue Squadron stuff, but it steered clear of the "main people".
Five years in, you get Thrawn.
Next year is Dark Empire, with Palpatine returning in a clone body and Luke dabbling in the dark side
Next year is Jedi Academy.
After that is a couple MORE instances of Palpatine trying to return and possess Leia and Han's third child.
Then the Vong come and kill a bunch including Anakin Solo and Chewbacca.
Then Jacen Solo (Han and Leia's son) falls to the dark side after that conflict and murders Luke Skywalker's wife. I kind of forget how it goes, but he ends up killed before he can establish his new empire.
Shit happens in life, especially for people so famous and instrumental to the direction of the galaxy. Frankly, between the two, it's like how people complained that Beast Machines wasn't a "proper" sequel because it took characters in a direction fans didn't want them to.