The only way Morrowind hasn't aged well is graphically and mechanically. It looks bad by today's standards, and the idea of missing a hit due to an accuracy roll in addition to your aim is a foreign concept to many of today's gamers.

It has a radically amazing setting that was literally written by a guy drunk off his rocker with benzodiazepines out his dumper. He also wrote Oblivion. Morrowind's setting is so unusual that the only reason it would seem banal is if you've experienced it dozens of times since you were a kid. It's also very brutal and real. The Dark Elves have their own word for foreigner. The setting doesn't 100% explain itself to you right off the bat. You have to look, read, think, and puzzle your way through.

I prefer SsethTzeentach's video on it the most.

Its main plot is actually some what reminiscent of Xenogears. Reincarnation involving other god-like beings, all intent on being or surpassing or killing other Gods. It's not a 1:1 but the Nerevar == Fei Fong Wong and Dagoth Ur == Krelian. Miang == Almalexia. It's still not quite as strange as Xenogears' plot, with the Zohar, Wels disease, all humans actually being synthetics, and Deus etc. But damned if the comparison can't be made.

The reason people give the current/later Elder Scrolls games guff is generally because they clip and compress the skills with each iteration, compressing/eliminating playstyles. For instance, there's no longer an, "Unarmored" skill that would let you build defense rating while wearing clothes not considered armor. As of Skyrim there's no longer attributes like STR DEX etc.

The first people to get interested in Elder Scrolls and cause it take off were more dedicated gamers, and/or kids who didn't know anything else, who liked/grew to like crunching numbers. Figuring out how to break the system. Reduce the player's ability to that, and they will naturally deride the entry that does it. It's that brand of fun that's led to modding being such a hot thing(you know, other than tiddy mods).