Looking over these posts, I'm leaning toward any problem with Supes being from a writing perspective, not a character perspective. I think he is still a very popular character. What kid-little boys especially-don't want to fly?
I do think though that one of Supes' problems has been relatibility. As audiences have gotten more sophisticated and perhaps jaded or cynical, the Dudley-Do Right way in which Superman was portrayed since the 40s perhaps just felt passe, and boring. I think DC eventually realized that and have tried to update the character several times since the 80s. The shows Lois and Clark and Smallville have also tried to make Superman more relatable, by focusing on "Clark" at the expense of "Superman". I think the themes of loneliness, of being an outsider, of being exploited, of misuing your powers or talents, of being a danger to the ones closest to you, I think these things could all be part of Superman's personal issues. Also, the very real problem that Superman can't be in all places at once and to some extent he has to play God in choosing what crises to deal with and which ones he should pass on. Also, whether he should just be Superman full time. I think there are occassional stories that deal with those pressures and perhaps there needs to be more of a focus of that aspect of Supes' dilemma. Another thing I don't think has adequately been explored in the films at least is the anti-Superman contingent. It seems like there would be strong opposition to him from some governments, even elements of the US government, there might be religious and other people protestors, just like I'm sure that some cults might spring up to worship him. These are all things to play with, if they haven't been played with before or a lot. I'm an off and on Superman reader so I don't know much about his comics history. In the comics, they have started playing with the anti-Kryptonian sentiment and I think that's a good direction.
As for Superman Returns. I think Singer tried to update Superman for the 21st century, I just think he did it in a bad way. With the allusions to being a messiah (yeah, I know I just said something about that in the other paragraph; but I would rather it be something debated among the characters and rejected by Superman than just to be portrayed as Singer did without comment), giving him an illegitimate son, having him stalk Lois, having him go back on his word (from Superman 2) about never letting the President down again. I also think he squandered Spacey, and provided way too few moments in which Superman was actually "Super". And Bosworth was the limpest Lois ever. But ultimately the misguided desire to make Superman Returns a sequel to Superman 2. I think Smallville does a much better job of updating the Superman mythos. The show is on the 9th season and he still hasn't put on the suit. That might be bad, but it shows that the writers have found a way to make Clark interesting as a character in his own right and that he doesn't need the suit on to be. Plus, Smallville has brought in some new fans who would've been turned off by the show if it had been Superboy.
I do think though that one of Supes' problems has been relatibility. As audiences have gotten more sophisticated and perhaps jaded or cynical, the Dudley-Do Right way in which Superman was portrayed since the 40s perhaps just felt passe, and boring. I think DC eventually realized that and have tried to update the character several times since the 80s. The shows Lois and Clark and Smallville have also tried to make Superman more relatable, by focusing on "Clark" at the expense of "Superman". I think the themes of loneliness, of being an outsider, of being exploited, of misuing your powers or talents, of being a danger to the ones closest to you, I think these things could all be part of Superman's personal issues. Also, the very real problem that Superman can't be in all places at once and to some extent he has to play God in choosing what crises to deal with and which ones he should pass on. Also, whether he should just be Superman full time. I think there are occassional stories that deal with those pressures and perhaps there needs to be more of a focus of that aspect of Supes' dilemma. Another thing I don't think has adequately been explored in the films at least is the anti-Superman contingent. It seems like there would be strong opposition to him from some governments, even elements of the US government, there might be religious and other people protestors, just like I'm sure that some cults might spring up to worship him. These are all things to play with, if they haven't been played with before or a lot. I'm an off and on Superman reader so I don't know much about his comics history. In the comics, they have started playing with the anti-Kryptonian sentiment and I think that's a good direction.
As for Superman Returns. I think Singer tried to update Superman for the 21st century, I just think he did it in a bad way. With the allusions to being a messiah (yeah, I know I just said something about that in the other paragraph; but I would rather it be something debated among the characters and rejected by Superman than just to be portrayed as Singer did without comment), giving him an illegitimate son, having him stalk Lois, having him go back on his word (from Superman 2) about never letting the President down again. I also think he squandered Spacey, and provided way too few moments in which Superman was actually "Super". And Bosworth was the limpest Lois ever. But ultimately the misguided desire to make Superman Returns a sequel to Superman 2. I think Smallville does a much better job of updating the Superman mythos. The show is on the 9th season and he still hasn't put on the suit. That might be bad, but it shows that the writers have found a way to make Clark interesting as a character in his own right and that he doesn't need the suit on to be. Plus, Smallville has brought in some new fans who would've been turned off by the show if it had been Superboy.