Let me preface this by saying that I started Elder Scrolls games with Morrowind, way back before the current console generation was even out. That is the benchmark by which, for better or worse, I judge all Elder Scrolls games. And you would find the combat in Morrowind absolutely atrocious. So atrocious you would begin to see Skyrim as the most engrossing and realistic thing in the world. Which is probably why I'm so accepting of Skyrim's battle system. After experiencing far worse, and even thoroughly enjoying it at the time, everything else is an improvement.

But anyway, while Morrowind suffered in the combat department, it was very successful in creating a rich dense world that it was incredibly fun to explore. It didn't have the AI that Skyrim does, so characters could only walk around in a limited range, and repeat the same tired lines, but that isn't the important thing for me when it comes to Elder Scrolls. What truly matters is the exploration, which is where Morrowind excelled, and where I fell in love with it. Skyrim's exploration is... lacking. Things aren't entirely scaled as they were in Oblivion, but the scaling and randomization is still there. I don't have a photographic memory, so it hardly matters to me if the last 200 dungeons were all beautifully hand-crafted and different from each other. In the end, they all blur into roughly the same thing, caves, corridors, all punctuated with the occasional chest or piece of loot. But when the loot is randomized the way it is in Skyrim, it stops mattering whether you visit every cave or not, because exploration can easily be replaced by power leveling somewhere and then heading to the nearest dungeon and ransacking it.

That's the first major strike against it. Second is the journal/compass/quest system. I don't like to use fast travel, and I don't like to blindly follow a magic arrow on my compass pointing me in the right direction, because both of these things break immersion and make me feel like I'm not experiencing the game properly. So I want to play the game as though I'm actually there, getting an important task and setting out to accomplish it, not merely checking off points on a list. But Skyrim does its best not to allow my way of playing the game, because of how useless most of the journal entries are, as well as the dialogue. Half the time characters never even give you directions or tell you where you're going, the data just magical turns up in your journal... or more frequently magically turns up in your compass. Using fast travel to get from point A to point B, talk/kill/acquire something there, and then return, is not my idea of a fun quest, but that's exactly what most of them come down to.

Third, the quests and factions are all substantially smaller compared to Morrowind or even Oblivion, and again suffer from poor immersion, which is that magical something that changes the seemingly monotonous process of looking at a bunch of pixels while pushing buttons into a fun and addictive activity.

Fourth, the level of depth in the game, in terms of armor, spells, skills, and attributes has really decreased compared to previous games. I'd be fine with them just streamlining the skills and attributes as they did, because there are some positive aspects to that, but I hate how the amount of armor you can choose from keeps decreasing, and spells have been absolutely gutted. Not to mention the constraints on spellmaking and enchanting.

That's about it, or at least all I can think of off the top of my head. It's been a while since I played the game. To summarize though, it's the fact that quests are boring, immersion spoiled far too often, and exploration virtually pointless, unless you do it simply to enjoy the aesthetics. Which I've done before, but there's only so many beautiful vistas you can enjoy before growing bored.