When Lattner talks about what Modular is doing, it sounds like they are planning to be almost like an operating system for AI systems, and Mojo is the language

When Lattner talks about what Modular is doing, it sounds like they are planning to be almost like an operating system for AI systems, and Mojo is the language you have to use. So it makes sense that it's not open, and you can only use it via their notebook. It probably doesn't work on normal hardware + Linux. That's the monetization strategy. You have to run their system and pay for it.