No reason for ME
As you said: dependents on personal usage.
My Win8 Server is just a big HDD for movies, music, videos, tv-shows...
And DE and now DrivePoole is so much easier then RAID.
I also run a 24/7 Hyper-V Server 2012 R2 Core with pfSense, FreeSWITCH, Win8.1 (for VoxCommando) and Debian.
But i wonder how Win8.1 can be not stable. I have ~10 PCs - DOS, Win95, Win98, XP, XP x64 and Win8 is something
that never made any problems. Even on 8 year old hardware with Vista/Win7 drivers it runs rock stable.
I'm not against somebody using Win10 and i didn't test it yet cause the last time i wanted to test it it didn't work
in VMWare. I'm just curios and wonder that Win8 is not stable and Win10 is.