Why don't video game developers create animated movies?

A lot of video games nowadays have cutscenes showing the background story. example

The video game developers could make an animated feature that combines cutscenes with some added animated footage. However, I find that there are very few, if any, movies that do that. Instead, studios tend to make dramas out of video games. Many of those dramas are mediocre at best.

I feel that people would watch an animated movie based on a video game, if the graphics are good. The video game developers have a lot of options. They can show the movie in a theater (2d, 3d or both). Or, they could just release it straight to DVD.

Any ideas on why video game developers aren’t already doing this?