Free software like TeX simply has an ethical basis which proprietary software does not.
… The computer world (and the non-computer world, for that matter) has become increasingly dominated by a very few large companies, as I mentioned. TeX resists that; it is simultaneously very idiosyncratic and very useful, and the standards mavens hate that. I love it.
Interview by Dave Walden for the TeX Users Group, 20050927, online at https://www.tug.org/interviews/berry.html, accessed 20120801.