Yeah this is a really good question. I'd love to know more about that too. There's some good history on the website here [1].

The creator apparently was selling it as freemium software in 1998, and then the bubble burst and the corp shutdown in 2002. But the creator created a non-profit called the Blender Foundation, launched a Free Blender campaign [2] (the forum post is still up!) to raise money from its users and bought out the rights to the software from the investors.

[1] https://www.blender.org/about/history/

[2] https://blenderartists.org/t/free-blender-campaign-launched/...