Why Not Linux?

In a previous post on Why Linux I asked why you should use Linux.

Today, I'll ask the opposite.  Why not use something else?  There are MANY options, even from Microsoft.  I am VERY interested to see the responses to this post :)

Here are some alternatives to using Linux and, yes, they do have valid use cases:

• Embedded operating systems:  very useful for hard real-time applications and for small processors limited in RAM/FLASH/CPU speed, and that don't need a full version of Linux:
• Arduino at http://arduino.cc/
• FreeRTOS at http://www.freertos.org/ (or use both in LIBMAPLE)
• Many other real-time operating systems....
• Or even no O/S (code to the bare processor)....
• DOS: for booting an X86 computer to run a simple test program or application:
• FreeDos at http://www.freedos.org/
• DR-DOS/OpenDOS at http://www.drdosprojects.de/ and http://drdos.com
• Free BSD:  for an even more permissive license than Linux - https://www.freebsd.org/
• Windows:  see below
• Apple:  see below
• Google Chrome or Android: (oh, wait, they are Linux!)

Why use Windows:   [disclaimer:  We own Microsoft Stock....]

• You want to play a game only available on Windows.
• You MUST use a piece of legacy equipment that came with a DOS or Windows-only driver and you can't afford to replace it with something that supports open source (time to replace that old Canon multi-function printer).
• When you MUST use the EXACT copy of Microsoft Word 2010 on Windows 7 to collaborate with others using the EXACT copy of Microsoft Word 2010 on Windows 7 to generate the exact, correct text for that document you are working on with extensive, unnecessary formatting.
• You need Adobe Photoshop or another tool not (yet) offered on Linux and that may have issues running under Wine. (Disney spent a lot of effort to get Photoshop to run under Wine.)
• You have to access or play media with Windows-only DRM and have no other choice.
• You must use it for a class to collaborate with others using the same commercial application required by your school (AFIK Blackboard does not support Linux clients).
• You want to BETA TEST a new user interface (Windows 8 anyone? Yes you!  No?) even after other users rejected that interface on Linux.
• You want to test the effects of a virus or analyze its operation (use of safe exe practices such as using a VM are recommended).
• You are developing viruses, Trojans, or malware and need a test environment (again, VMs are recommend).
• You need to use SharePoint as it is your absolute best solution, for example for configuration management (no, can't spell GET or GOT or something like git, much less dripple or dopple or drupal).  
• It is the standard required by your company, school, or organization.    
• You work for Microsoft.

Why use Apple Products:

• You think Apple is cool!
• You need to do professional video or sound editing.
• You want a commercial, supported desktop that can run lots of tools not yet available on Linux, but that is not Windows.
• You like the Apple design and operation, and that it is based on Unix.
• It is the standard for your company, school, or organization.
• You work for Apple.

For Servers:  Use Linux

For development desktops:  Linux (unless you absolutely must use Microsoft tools)

For hosting VMs:  Linux

What are your thoughts?  Any suggestions?