Uwe Boll might get his hands on it. That's the only reason one needs to be against the idea of a Fallout movie.
Serious reply: Would I like a Fallout film? Yes. Would I like a movie for movies sake? No. Only if it was choreographed by loyal fans of the series who KNOW what they're doing. Unless the movie was on par with the length of LOTR trilogy, I don't see it as being fair to the lore. A video game works because you can go through it all at your own pace, and it takes years to develop a game. Movies are like condensed books, but also cutting out the best parts of a book for 'time' or 'interest' sake.
As a TV show, I'd again like to see the hypothetical series follow true to the series lore as well, not straying randomly off to its own road.