There are a lot of business models around open source software. It's obviously not as profitable as closed/proprietary. I think what a lot of "free" advocates would argue is that free software is much more valuable to end users because of its transparency. The truth is that its more valuable to some people. 

For example, if you're a company needing a web server, you get a lot of extra value out of Apache httpd being open source. Not only do you have the code that you could muck with, but there's a whole community of people with the code that you can draw upon.

If I'm buying a laptop computer, I'm probably not going to get as much value out of an open source operating system. The things that add value in the above case are not applicable. Why? Because if I need to muck around with the OS, then the OS is a poor choice. 

Just keep in mind the end user's perspective. There is already enough useless software in this world. 