A future for the Windows packaging situation.

[Hécate]

 >Hopefully that wouldn't become the only way to download GHC.

That wasn't my intention to suggest it to be the One True Way to 
download it.

 >Sounds great, but is it reasonable? GNU/Linux package managers AFAIK 
don't install Haskell libraries either

Some do! On Fedora, the Haskell libraries that are shipped are prefixed 
with `ghc-`, and Arch Linux has become
quite infamous due to the way they ship dynamically-linked Haskell 
libraries and executables.
By GUI I was thinking of something like DNFDragora[0] and its Ubuntu 
counterpart (whose name I forgot).

 >It's true that one-liners and scripting is harder in Cmd, but simple 
commands (no pipes, no flow control etc.) that are the bread and
butter for developers work just fine.  I sense I'm missing some context; 
why is this an issue?

cmd.exe is fundamentally a foreign interface to most Windows users, even 
for developers. IDEs and GUIs have reigned for a long long
time in Windows Land, and Microsoft has no will to change this state of 
fact. WSL is a tool developed to Linux / macOS power-users
who incidentally need to deal with Windows, or needed an argument to 
switch to the platform.

In addition to all of this, shipping a .tar.lz format was a terrible 
mistake, for no tool shipped with Windows is able to properly
handle it, but I do not wish to blame anyone, it just needs to be 
changed to .zip and we can be done with it.

[0]: https://github.com/manatools/dnfdragora