You guys all pretty much nailed it, so, I can only really reiterate a few points:
Brandon Routh
I feel for him. A role like that is a leap of faith. I'm not even sure he got to read a script before he signed on, yet, there he was top-lining a hugely expensive, high-profile summer blockbuster with everything riding on his shoulders and almost no say in the creative process. It's tough to imagine that, even if he was bothered by the script or the costume or some of the casting choices, there was anything he could do after saying yes: he was arguably the lowest man on the totem pole in terms of leverage - despite being the star - and it really had to be just a matter of him crossing his fingers and hoping the production didn't screw him over, which leads to:
Bryan Singer
He should've just made the movie he wanted: "a story about what happens when an ex comes back into your life". The character of Superman didn't need to be anywhere near that. He also should've realized that casting Brandon was a mistake. I don't blame BR for taking the part, but dude wasn't ready. HC is roughly the same age now as BR was when filming, yet appears instantly more confident, charismatic, and comfortable than BR, largely due to his lack of experience and the job description ("play the CR Superman/Clark"), plus what had to have been one h*ll of a case of bubble-guts taking on that kind of responsibility.
Some people are Michael Jordan, most people are not. Sure, someone might be
good at their job, but whatever IT is, they don't have IT (or, not yet). Even CR seemed older and more mature than he was. BR looked like a kid. It should've come down to a screen-test, period, and not a first impression over coffee. I almost get the feeling that BS (like a lot of directors) developed a crush and that his cloudy-judgement is what betrayed him. He also should never have cast Kate Bosworth. With
any film you only get so many chances to ask an audience to suspend their disbelief - we're already dealing with the fanstical in Superman, himself, you don't stretch credulity further by having the two leads appear younger than the versions of themselves that were supposed to have existed "5 years ago".
Costume
Beating a dead-horse, but funk it: it didn't look good on Routh, doesn't look any better on a manniquin, and shouldn't have existed in that form. Singer picked a costume director who's tastes and talents didn't line-up with the property, giving us a bunch of flourish and "cutesy" stuff that isn't Superman. The costume is, already, enough of a SOB (suspension of disbelief) without ridiculous tiny S-shields and a plastic belt and cape that made it look like Clark got hold of CAD software and a vacuum-forming machine and went bug-nuts.
Story
Also said a bajillionty-six times: you don't continue - vaguely - a nearly 3 decade old story by skipping over the last 2 parts and then cherry-picking random plot points from the rest - vaguely. And if you do, for the love of God don't just remake Superman 1 with a kid and cellphones. What's shocking isn't that WB OK'd it (Singer
was on a roll and studio suits have zero creative instincts with which to judge an idea that bad), but, Dick Donner, et tu?
The pitch must've been: "let's cast a new actor to portray the same version of Superman/Clark that Chris Reeve
owned, and we'll ignore the last few times we actually saw that character on screen and instead do a quasi-sequel to the sequel from waaay back in 1980 that at its heart is really just a love-story about that one f***king ex that shows up at your door just when you've got your life back together and - uggh, don't you hate that?! Gah! Plus, it'll have cool special effects sometimes and others it'll just look like Polar Express Superman, and oh! our main characters will look de-aged somehow." Whatever drugs BS and WB and Dick Donnor were on? I want those
