Really, with Linux (or a BSD), you can make tweaks for free to save memory and to only allow specific tasks and hardware. Plus you could publish these changes

Really, with Linux (or a BSD), you can make tweaks for free to save memory and to only allow specific tasks and hardware. Plus you could publish these changes and maybe they will be accepted by upstream. With Windows, you need to beg and pay Microsoft for customizations and hope these changes will not cause other issues. Plus, most space projects are on a tight and limited budgets where management would rather spend on hardware than software.