I wouldn't even blame Microsoft for this one. Most software written would reference the C: drive since it was the standard configuration. Now days with smaller SSDs being more common and with some "out of the box" configurations coming with an SSD backed by a larger HDD the support has only gotten better. I would say quite a few software packages are getting better at being run from non-standard locations, especially game launchers. Origin, Steam, Blizzard, GoG, all have options to move games and/or rediscover games that have been moved.