That's true, and it is a reason that free software with a public VCS history is really the gold standard.
I've worked with enough non-commercial but restrictively licensed academic software that I'm willing to forgive commercial vendors for similar transgressions, so long as there is full source available to licensees.
Though I admittedly steer clear of restrictively licensed code when at all possible now. I gave up on GAMESS and switched to really open quantum chemistry software because I tired of not having any revision history in the source tarballs, and of having to re-agree to the license every time I wanted an updated version. Also because I want to build software that can be installed in a fully scripted headless manner, and a "fill out the license agreement" step precludes that.
I've worked with enough non-commercial but restrictively licensed academic software that I'm willing to forgive commercial vendors for similar transgressions, so long as there is full source available to licensees.
Though I admittedly steer clear of restrictively licensed code when at all possible now. I gave up on GAMESS and switched to really open quantum chemistry software because I tired of not having any revision history in the source tarballs, and of having to re-agree to the license every time I wanted an updated version. Also because I want to build software that can be installed in a fully scripted headless manner, and a "fill out the license agreement" step precludes that.