Look at your examples for server stuff: it would make no difference to the end user if those were running on Windows or not. IIS gets value from ease of .net application deployment, SQL server from playing well with .net
IIS also gets value from Windows account permissions integration, from Computer Manager integration and MS Best practises Analyser, from PowerShell and VBScript and Visual studio integration, from Windows certificate services integration, blah blah.
The "Windows" benefit is integration, Microsoft products aren't standalone.
What benefit rewriting everything for Linux? Except alienating a huge chunk of Linux-ambivalent administrators.
IIS also gets value from Windows account permissions integration, from Computer Manager integration and MS Best practises Analyser, from PowerShell and VBScript and Visual studio integration, from Windows certificate services integration, blah blah.
The "Windows" benefit is integration, Microsoft products aren't standalone.
What benefit rewriting everything for Linux? Except alienating a huge chunk of Linux-ambivalent administrators.