Being the Hulk fan I am, I often lurk around the Incredible Hulk message boards and such. Because of this I have spent the last little while thinking way too much about "zero gravity". The discussion comes about from Hulk #5 obviously and just how the Red Hulk was able to wield Mjolnir. But the question I've been asking myself is "does science belong in comic books?" Should we care whether the Flash could truly run up a building? (I recommend "The Physics of Superheroes" by James Kakalios for the answer to that question and many others, some of which I might mention here) Should we wonder whether the Atom would be able to breath after shrinking down? About the only answer I can come up with is "That's entirely up to the individual reader."
What a cop out huh? But really, who am I to say what readers should be looking for in comic books? So it's entirely up to you. As for me, I have my own take on it. I like talking about these things, I tend to have a weird facination with this sort of triva. So does this mean I look at every comic looking for instances that heroes defy science? Obviously not. I think I'd go insane to try that even for a month. But that doesn't mean I won't take a second look at things just out of curiousity. Now does this mean I'll be critical of a book (or tv show or movie or whatever) that doesn't match? That depends.
On one hand, if it's clear the science isn't important to the story then I just chalk it up to random trivia. It doesn't effect my view of the story so I'm able to look beyond it. I'd put stuff like the original Star Wars trilogy and Firefly/Serenity into this category. Lucas and Whedon didn't want to be bogged down by the science of it all so they chose to keep it out. Whedon even had Captain Reynolds break down one situation as something like "Without this ship don't go?" while holding up ... something. Whedon clearly didn't want to get bogged down in the specifics of it all. So I can appreciate a good conversation of things they may have gotten wrong but it won't change my appreciation of the movies/tv shows/comics.
On the other hand, you have the writers who choose to use science. You more likely to see this in something like Star Trek (the Next Generation and such). With this sort of thing the writers often introduce something scientific as part of the show. They use science to explain why something is impossible or how they get around a difficult situation. And this is where things differ for me from the first scenario. If you are going to introduce a solution to a problem or situation based on science then you should work on getting your facts straight. Now obviously there are some things they'll never be able to explain and I understand that. And sometimes you just have to believe someone along the way invented a doohicky device that solves a problem we currently don't know how to solve but if they get basic stuff wrong then I do get disappointed. That hits me as being a bit lazy, using a solution to your story that we already know is incorrect.
So what is the Hulk example for me? I'd put it in the latter. Loeb wanted to come up with some way for the Red Hulk to wield Mjolnir and he decided to have him do it in space. After all, Iron Man has done it. And it gets explained as "zero gravity" or as Quesada saying "once in space, void of gravity". But then it becomes a problem because they are clearly not understanding that there is gravity in space. At this point they appear to be using their own misconceptions to explain something and yes, I will be critical of that because they are making it a point of the story. If they had have left it at pseudoscience or up to the interpretation of the readers then fine. But if I see them say something wrong, I want to call them on it.
Now I can understand why a lot of people don't like this approach. They just want to sit back and enjoy their comics without putting so much thought into it. They just want to take it as fact that the Red Hulk can do this because of "0 gravity" and because, let's face it, he did it. And that's fine. I might be a little disappointed that these people don't have the same curiousity to understand how things work that I do but really, when is a very basic understanding of space travel going to help me in life? But I really can't change who I am. So for me, yes, science belongs in comic books but I'm not going to lose sleep over it.
Oh who am I kidding, I probably will lose sleep wondering if it's possible for the Flash to jump up and touch a ceiling fast enough that people won't notice or some other useless trivia. :)