In my opinion, Oblivion was a far better Role Playing Game than Morrowind was. No matter what character archetype I started with in Morrowind, they all became the "All Powerful Nerevarine" by the end of the game.
You could get your skills maxed out in both Oblivion and Morrowind. Every character can become the Nerevarine or the Champion of Cyrodiil. There is no difference in that aspect and basing any argument off of it must take into account that fact.
As for me, I do not hate or dislike Oblivion. It was a fun game, but it sorely disappointed me. Many aspects just felt wrong. Cutting out magic like teleportation, cutting out skills like Spear, cutting out weapons like spears, crossbows, and throwing weapons, making many of the encounters leveled (which made the game feel the same no matter where I was), etc. In Morrowind, there were many armor and weapon sets to choose from. Tons of skills. Enemies leveled sometimes, but mostly out in the world. Many parts of the world were scary and dangerous before you got strong enough. It really gave you a sense of progression, from pissing yourself as you entered your first Six House base, where many of the enemies there were very very dangerous to your, to finally getting so strong you bust in like you're the baddest hero in town, streaming with enchantments and wielding ancient arms and armor. In Oblivion, I can kill Umbra at level 5 and get a worse sword than if I had waited. How ridiculous is that?
But regardless of what Oblivion did, it matters what Fallout 3 did more. If fixed EVERYTHING I hated about Oblivion. Its level scaling made sense and still provided challenge. It had a wider array of weapons and armor. Some of the skills from Fallout 1 and 2 got cut, but the cuts made sense and all of the old functionality was still there, just moved a bit. Combat felt smooth and, even better, the dialog was great. I could be a nice guy, I could chose not to care. I could be an ass, or I could just be out for my next stack of caps. I rarely felt there was a situation in Fallout 3 were I didn't get as many options as realistically available. In Oblivion, most dialog options didn't even matter, because the answers were always the same.
I feel Oblivion was a try at reaching out to a newer audience. It worked, but they certainly realized that their system was not perfect. Even before Fallout 3 was made, you could see their attempts to change things with Knights of the Nine and Shivering Isles. I have high hopes for TES V. Lets hope its a game that we can all enjoy.