Because it's a good server O/S but a poor (!) workstation O/S? Anyone with even passable IT skills can keep a Windows machine running well and keep it secure. Running Windows opens up a world of programs than can only be run on Linux with difficulty...
Office docs, any graphics operation, play/edit/create any media file, surf the web, download videos from hundreds of different websites including youtube, bitchute, rumble and most any video on a web page, email clients, unit conversion, Spotify app, VPN app, file archive of any type - not just zip, torrent client, Nextcloud desktop client, ebook library and editor, burn USB thumb drives and optical discs, full blown accounting app, screenshot tool with instant upload to imgur with url auto-copied to my clipboard. Haven't paid a dime for an OS or software in that same 10 years.
Specialized business apps like my auto repair stuff is not available but for a personal desktop, general purpose business desktop/client, it works fine. Microsoft locked up the rare use software over the decades because Gates cornered the OS market.
Just virtualize windows. On my deb home server with multiple passthoughs I can game locally, and do rendering/cad remotely when latency isn’t an issue. On a T480 with 28 hours of screen time thanks to Arch I can access 1kw worth of processing power and never worry about the battery, or my processes ending when I shut it down.