I think more professional codebases will wind up being open source in the future. If your product is not the code itself, and it rarely is, there is little sense in closing it off. In the short term, it still makes practical sense to keep things closed, but I think things will trend towards openness.
We plan to make this website, dev.to, open source, and I'd be game to try something like this even before we get the open source project out the door. I've been itching to get some total outsiders to look at some of my decisions and criticize, ask good questions, and help us clean up the gunk.
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.