I always figured screenwriters for disaster blockbusters, crime dramas or sci fi shows write for some sort of hypothetical John Q. Public; someone who's neither a physics aficionado, an occasional planet-watcher, a nature enthusiast or even an erstwhile watcher of something like the National Geographic channel. With that type of audience in mind, and as they incorrectly assume that 99% of their audience is going to be made up of brain-dead ignorants, they cobble things together.
Why bother to do otherwise, when the board evaluating the movie as a funded project are probably old geezers who don't give two shits about basic quality, as long as returns are made?
Besides, trying to reach some sort of common ground between Real Life Hacking and Hollywood Hacking would be impossible. One side would still be bored out of its mind, the other would still clamor that it's not an accurate representation.
Honestly, the only two techie movies I know that come even remotely close to handling hacking correctly are The Matrix (for the few shots you do see a computer screen in, across all three movies - Trinity's hack from Revolutions is done in a Unix prompt, I think) and Tron Legacy (again, recognizable Unix prompts in the Real World sequences).
Not that they're prefect representations, though. Far from it. They're the best we've got, frankly, seeing as we have to choose between this:
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And this:
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And this:
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...I know I'll pick Option A. Option C might be feasible within the boundaries of a real system, but it's boring for your average viewer. Option B treats those who do know a tiny bit about I.T. like complete idiots.
Generally speaking, I'd say I'd like for any vaguely techie-inspired movie or project to have an honest consultant on board. Not that it's in any way guaranteed, seeing as I remember watching a B-grade horror flick Cliff Blezinski had participated to as a consultant (kids being killed for realsies by NPCs in some hot new underground game exchanged on burned DVD-ROMS) and realizing they'd probably just paid him to have the right to attach his name to the project.