I work in places with lots of old systems and no record-keeping for licences. When that proprietary stuff needs to be re-installed, I just replace it with FLOSS equivalents. It simplifies my life greatly. If a certificate of authenticity is missing from a PC, I replace the OS with GNU/Linux as well. I am instituting backups/imaging/record-keeping so this may be less of a problem but FLOSS is much easier to manage. I only need one image of GNU/Linux that will run on all our PCs. I need four images of XP. When the time comes to kill XP, I can use the imaging system to deploy GNU/Linux in an evening. This proprietary stuff is too much work. I want to work for my employer, not some software vendor.