The series probably could do with a bit more problem solving. Yes, just going around, killing enemies and exploring dungeons is fun and all that, but this isn't a linear first person shooter, a game with as much content and freedom as the Elder Scrolls series promises should be able to include more than one type of challenge, especially since not every character players can create must be a warrior, so naturally, not every challenge should be targeted at combat classes. I would be nice to see if some locations in the game required you to complete puzzles rather than just killing enemies. This is something that recent Elder Scrolls games tend not to offer, in Morrowind, about the only major intellectual challenge I've ever faced is figuring out how to find a quest objective from at times vague directions, and in Oblivion, the addition of a compass that would tell you exactly where to go often took out even that.
Graphics have always been a part of video games, including TES series. It's not better graphics that are responsible for lower quality games, it's something else. Oblivion is just as much of an Elder Scrolls game as the others and it's just as good.
I have to agree here, blaming all your complaints with games on graphics is far too simpleminded, and doesn't begin to adress things. There are a lot of factors that can effect individual aspects of a game, and in the case of Oblivion, or any other game, it's hard to say which ones are responsible. And what are people going to blame if a game has terrible graphics and still doesn't have everything they hope for in it?
Besides, it's not like developers are going to stop trying to improve the graphics in their games just because some claim that this effects the quality of their games, as long as new computer hardware is released, developers will continue to take advantage of its abilities, this is perfectly normal, and when all the competition keeps making the graphics better and better, individual developers would be foolish not to have at least a devent level of graphics quality as well. Of course, not every developer will go try to make games with cutting edge graphics, but you probably won't find many modern, professionally made games created by major companies that are intentionally made to have extremely dated graphics either. It doesn't matter how much content a game has, how deep the story is, or how much fun the game is, if the graphics are so hideous that the moment gamers see the screenshots they look away without actually bothering to find out how the game
plays, it's all meaningless. Not to say that every player will do this, but I'm sure some will.