The importance of writing in videogames is a tad overrated, since the implication is that only the writing, dialog, and story are what's important. I'd argue that two other things are equally as important, if not moreso: immersion and world-building. A lot of games does this really well. I'd point to a game like Batman: Arkham Asylum. Is the writing great? Not really, it's just okay for the most part. Same for the voice acting. BUT it does a really great job of immersing you into the role of Batman and also in building the world in a way that aids and enhances this immersion.
Movies, TV shows, books, and so on, are far less likely to offer that level of immersion and trying to make some 1:1 comparison between writing in one and writing in the other is never really going to pan out. Now, that doesn't mean that writing in videogames should be shoved to one side and forgotten, it's certainly got its role to play and it would be nice to see a bigger emphasis on it, but pulling that one aspect out and trashing it kind of ignores that larger picture of what a videogame is and what it sets out to do.
