Re: Video Editing
Pixar and other 3D animation studios develop their own software, and they don't have video footage taken with cameras, they have just rendered images. Linux clusters for such tasks make sense.
But what they use for the final editing? For example, Disney for 'the Force awakens' used Avid tools. I'm sure most of the CGI rendering has been done on Linux, but the editing has been done on Avid, and that means Apple or Windows.
Editing video footage shot with cameras is a different job. And like any professional job, money matters. Subpar tools with subpar support for cameras and editing devices are not what you're looking for. The price for the tools are just a small fraction of the overall expenses, but the time wasted to achieve the desired result can be very, very expensive.
Take a trip, if you like, to the Canon new Burbank facility, where movie makers can test their equipment and edit on the tools their used to, and see what's in use.