I don't care much for it being open source or not, it's just a shame Apple is making attempts to limit its use cases through licensing [1]. It's on brand for Apple and totally expected, but still sad. It's not going to stop a bunch of homebrew efforts springing up around it, but it will likely be enough to stop third party app stores like Steam from opening up a huge game library on the Mac in a straightforward way like what happened with Proton.

[1] The license is probably actually meaningless in a lot of jurisdictions, but it still has a chilling effect for commercial parties using it. That's probably exactly what Apple intends.