[XBigTK13X]

That's a great question.

Obviously, I am simplifying a complicated legal system with my reply. I am not a lawyer, but I have studied open source licensing.

With some exceptions, the Linux ecosystem does not eclipse for-profit software. You are free to run closed source software within an open ecosystem.

With that said, I personally develop and sell open source games. Linux is a first-class citizen in my market. I find that the person who makes the decision to run Linux as their main OS is the same type of person that will avoid a purchase of software that is closed source. In that case, the barrier is the mentality of your users rather than licensing restrictions.