For academic labs you can add 'perceived future commercial value' to that list. In my experience these groups are often run by people with little or no commerc

For academic labs you can add 'perceived future commercial value' to that list. In my experience these groups are often run by people with little or no commercial experience and lack the skills to appreciate the difference between a prototype and a commercial solution. Coupled with the pressure from Universities to 'commercialize all the things' this can inhibit attempts to distribute the code freely.