Maya's grip on the VFX companies is, I suspect, in part due to how Maya has been built into the pipelines and tools that many companies use, which is only possible because of Maya's fantastic API. I haven't used the API in anger in about 10 years, but it was amazing back them. Very well designed.

Now if Blender had a comparable API that VFX studios could build on Blender would have a better shot at eating Maya's lunch. I predict that smaller companies with smaller budgets and almost no custom software will be the early adopters of Blenders and will pave the way for bigger companies.