I’m quite excited about Blender’s growing popularity.
But, FWIW, I used to animate effects at PDI/DreamWorks, and we were using Maya. Today I think it’s Houdini. In my time, modelers were using Maya as well. We had an in-house character animation tool mainly because the character rigs were custom, evaluated with an in-house scripting language, and Maya couldn’t evaluate them.
While costs are always scrutinized, the decision to use Maya had very little to do with the price of a seat of Maya. It was just a tool that many people knew already (which is a huge factor in cost, BTW) and it also did most of the things we needed to do.
All the in-house tools were constantly scrutinized for cost, and usually the question was not whether we could reduce costs by building in-house, it was the other way around: can we reduce costs by purchasing off the shelf software. Remember that each and every developer is a 6-figure salary, which can buy a lot of seats of Maya. Note this applies to contributing to Blender too... it’s very expensive to contribute to Blender, so it really has to be appreciated when it happens!