If MS would package just the header files, they'd probably get tons of complaints about compilers complaining about missing libraries, missing dependencies and toolsets not being available.
The Windows SDK is not just a few C++ headers and a bunch of lib files to link against. It has a huge surface area. The documentation and toolsets assumes all API calls from Windows 3.1 APIs to UWP to be available.
The SDK download (ISO format) is 1.1GB in size, requiring a total of 4GB of disk size to install (whether this includes the size of the installer itself is unclear). Big, but not unavoidably so, and you can pick and choose some features. It bundles debugging tools, the application identifier, a certification kit and MSI generation tools along with its headers (which seems fair to me); less than 1GB of extra kit on top of 1.8GB of headers and libraries you probably want as a Windows dev anyway. Just the headers won't leave you with a working dev environment even if you bring your own debugger.
Unlike what some developers seem to think, you don't actually need to download Visual Studio to get the SDK, you can also download it separately from the website [1]. Pick the ISO version and extract the CAB files yourself if you want to manually pick and choose your files.
The SDK ships as an installer but that just makes sense. Ubuntu ships their headers in DEB files as well, for example. You want to be able to add and remove these packages as you upgrade or downgrade your target API levels without having to manually set up a file system hierarchy.
As for non-GUI interaction: `WinSDKSetup.exe /quiet /ceip off /features DesktopCPPx64` will install only the necessary headers and libraries for x64 C(++) development in the default location without sharing data with Microsoft. Found this command line with `wine WinSDKSetup.exe /?`. You can also add, repair, and uninstall packages with the same installer.
The Windows SDK is not just a few C++ headers and a bunch of lib files to link against. It has a huge surface area. The documentation and toolsets assumes all API calls from Windows 3.1 APIs to UWP to be available.
The SDK download (ISO format) is 1.1GB in size, requiring a total of 4GB of disk size to install (whether this includes the size of the installer itself is unclear). Big, but not unavoidably so, and you can pick and choose some features. It bundles debugging tools, the application identifier, a certification kit and MSI generation tools along with its headers (which seems fair to me); less than 1GB of extra kit on top of 1.8GB of headers and libraries you probably want as a Windows dev anyway. Just the headers won't leave you with a working dev environment even if you bring your own debugger.
Unlike what some developers seem to think, you don't actually need to download Visual Studio to get the SDK, you can also download it separately from the website [1]. Pick the ISO version and extract the CAB files yourself if you want to manually pick and choose your files.
The SDK ships as an installer but that just makes sense. Ubuntu ships their headers in DEB files as well, for example. You want to be able to add and remove these packages as you upgrade or downgrade your target API levels without having to manually set up a file system hierarchy.
As for non-GUI interaction: `WinSDKSetup.exe /quiet /ceip off /features DesktopCPPx64` will install only the necessary headers and libraries for x64 C(++) development in the default location without sharing data with Microsoft. Found this command line with `wine WinSDKSetup.exe /?`. You can also add, repair, and uninstall packages with the same installer.
[1]: https://developer.microsoft.com/en-us/windows/downloads/sdk-...