It has nothing to do with "employee vanity" and that's one of the stupidest things I've ever heard.
There's a simple reason Blender doesn't see much use in film production: Support. There is no way the Blender Foundation could provide the level of support that a company like Autodesk does. When you run into problems you call your enterprise support team and get it fixed. This is why you pay them the big bucks. Their support staff does nothing but fix problems, where anyone that you could hire to do the same would necessarily spend most of their time sitting on their ass doing nothing since stuff just doesn't go wrong all that often. That alone will keep Blender out of a LOT of shops, especially those that are just large enough to be working on major projects.
The idea that a company should just hire a programmer they don't otherwise need just so they can make some software work is asinine. That's like saying a home builder should hire a full time auto mechanic instead of taking their work vehicles to the shop when they break down. No, hiring a guy will not offset the cost of purchasing licenses and support. This is especially true when you hit one of those moments where things get so shredded that the cost of enterprise support seems like a bargain.
There are other, more technical, issues that keep Blender from being used much. Chief among them is that it isn't really exceptional at anything. It's not uncommon for things to be modeled in one program, textured in another, then imported into another for animation, and then brought into a final one for lighting and rendering. There are better programs for modeling than Blender. There are better programs for rendering, texturing, animation. Blender is oatmeal. It's there, it works, but it's not really great at anything and as a result has never found a niche.
Because, ultimately, that's what it's all about.