If it's so easy, which are these ways, then? Do you think they'll remain available indefinitely?
Not that I don't underwrite the risks involved in getting your OS from untrusted or unreputable sources
Not only does it allow you to create a local admin account, but you can also skip all the other setup screens that you want by pre-supplying values. Throw this file into your Windows boot media, do a fresh install (which you should be doing when you get a new machine regardless), and away you go. I use this both personally and my work environment. Not only are you then not relying on modifying OS ISO's or compilations, but an XML file is relatively easy to verify that only the settings you have set are the ones being input into the system if you utilize a third party tool like the one available at schneegeas.de
I suppose I might still be worried about targeted offline-acting malware if I were using Windows to control some enrichment centrifuges or something. But apart from that, I'm fine with whatever inhabitants it may have frolicking in their isolated jungle.
There are trusted tools out there, like Rufus, that will enable workarounds for you if you tell them to create bootable media. Tools with developers you can look up, rather than anonymous pirates.
As far as installation process:
If I go to the site of any libre project that doesn't install through nix/apt/etc, it will have a focused list of directions that I need to do to install it.
If I go to Microsoft's site and search for how to install Windows, I will be greeted with a deluge of articles I need to read and understand all of the various different methods and scenarios (after avoiding the links to BUY BUY BUY. I already have plenty of Windows licenses that were anticompetitively bundled with every old laptop I have sitting around, thank you). And then since I want to avoid their consumer install methods that insist on holding victims' wrists, I will likely need to go an eNtErPrIsE route - meaning even more reading between the lines of overwrought bullshit.
Whereas if I download a torrent of Windows, it will come with a focused list of directions that I need to do to install it.
BTW doesn't Rufus only run on Windows? That's kind of pointless for me. My workflow is virt-install --cdrom /path/to.iso
Perhaps I will look into setting up a "KMS server" next time I need to reinstall, but I would guess it's a bunch of admin tinkering for not much gain. The kind of admin work that will have fallen apart in the few years before I need it again.
... doing a quick look it seems like "KMS server" only runs on Windows itself? And there is a libre reimplementation for Linux, but it doesn't seem to be in nixpkgs, and requires setting up a heavyweight "Domain" with Samba? A few lines in smb.conf or nixos config and I'd be game, but no, it looks just as bad as I thought it would be. Please correct me if I'm missing some way that is actually straightforward and simple, but this doesn't seem to be the case!
So yeah in short, that's why.