Lemmy.ml devs own the repo, it’s just licensed as open source software under the GNU AFFERO GENERAL PUBLIC LICENSE. You can read the license in the repo files. So you can fork off it and run your own instance. If you go to GitHub.com/LemmyNet you see the two people who are members of the project, with the accounts, both have Fidel Castro avatars.
Personally I think having a bunch of socialists run the software, is by definition the best way to have it avoid corporate interests.