"but as a free OS..."
There's a missing apostrophe there. It's "free" in that it doesn't come with a price-tag. It's being paid for, just in other ways. It might seem nit-picky, but to me, at least, it's an important distinction. Facebook is "free" also, but you're paying for it by looking at ads. Google search/email is "free", but you pay for it with ads.
I personally hate the idea that something is "free" but you pay for it with your time/eyeballs. In some regards (like this) I am old-school. I like the simple model of I pay $X for Y product, done.