:Sorry for the belated answer, FHT: 
 :1) If (and only if) you can reach consensus that the current crop of sources is "looney tunes", then yes, your comparison to 9/11 is relevant. But I fear the opposite is much more likely: that the consensus instead is that our current selection is correctly mirroring the general view: that Gravity really is described as a sci fi movie by a significant number of good sources (mainstream movie news magazines). 
 :Your thoughts on sources using words "wrong" is an interesting topic in itself (my view is that the way a word is used defines its correct usage) but we'll have to discuss that elsewhere. In the meanwhile, I am afraid Wikipedia counts your (or my) opinion as "original research" unless we're published in a "good source". The definition of sci fi simply isn't as stringent as you might wish it to be, and ultimately: it is not Wikipedia's job to change how and where "sci fi" as a label is applied. In short: Wikipedia doesn't lead, it follows. 
 :2) First, "science" <> "science fiction". They're completely different labels. Nobody is claiming Gravity has science in it, they're just claiming it to be science fiction ) Second, you seem to labor under the misinterpretation that a work can't be sci fi unless it has "science" in it, which is clearly an unsupportable position to me. I think (but feel free to correct me) your argument is really that the movie only depicts current, rather than future, tech, and so isn't sci fi. But again, this boils down to the (from your perspective) unfortunate fact that movie genres really have no other useful definition that "what people use to call films" ) 
 :Regards,