Why I Still Use Windows
2nd Reason - Adobe Applications
The professional market might not be too large but they are certainly profitable. They are currently dominated heavily by Adobe and Autodesk. While Autodesk has been known to support Linux from time to time the same does not hold true for Adobe.
Of course I am not counting runtimes. Thankfully Adobe at least allows the finished content to be displayed on Linux devices albeit that is not what I am talking about here.
Price is not what is keeping people on Windows and Mac. If an alternative operating system is offered there will certainly be some who will switch. I would prefer to continue to use Adobe products for multimedia creation as I have been trained upon it. It would be difficult to get accustomed to alternative software and there are some things which just are not possible with alternatives at this point in time.
What they can gain:
There are two main ways which Adobe can capitalize on a transition to Linux.
When I started being serious with 3D content I purchased an educational license of Maya 8. For several years I used that education license to learn the practice and create some noncommercial content for video games. I became quite good at learning the nuances of Maya and developed a style with the program. Blender is a free application developed by an open source community under the Blender Foundation. For years I have been trying to switch to Blender but it never quite had the features which I desired to get in the groove.
At some point last year Blender underwent a series of major updates due in part to the Google Summer of Code initiative. Once BMesh was added to Blender and allowed models to contain polygons with 5-or-more sides Blender caught up with what was holding me to Maya. Once Blender eclipsed my usage of Maya the barrier to switch was low enough for my usage and I have not looked back since except to export some old work into an open file format.
One of the main features holding me to Photoshop is the lack of reasonable support for layer styles in GIMP. If Adobe ignores Linux all they will accomplish is frustrating users who would prefer Linux into supporting open source alternatives. Blender beat Maya. There is no reason why GIMP or a similar program could not outright beat Photoshop. There is no reason why Inkscape or a similar program could not outright beat Illustrator. There is no reason why Krita or a similar program could not outright beat Painter. Why would you boycott the, at worst, niche community who are most likely to contribute to your free competitors?
Aside: Near the end of writing this editorial, the Blender Foundation released their Mango Open Movie project titled Tears of Steel made with the above mentioned open source software along with MyPaint which I omitted due to its similarity with Krita.
This brings me to my second method how Adobe could capitalize on Linux: you want users to switch to subscriptions anyway! What better way to encourage users to subscribe to your software than to provide them with platform agnosticism?
Come on Adobe! Let your users log in to Creative Cloud and download the latest version of your software on whatever platform they desire.