Windows 8.1 does really badly with SCP Containment Breach, because SCPCB uses Direct X 7 whereas Windows 8.1 is DX11/DX12.
The fuck are you getting your information from.
Containment Breach runs fine on Windows 8.1, it's really just the screen bug where the bottom half of your screen in fullscreen is flickering like crazy. It doesn't do badly, it's just the occasional shitty-bug from time-to-time, something that's known for this game.
It's not only Containment Breach that uses DirectX7, it's Blitz3D overall. There's also a DirectX9 and 11 port of it going on the one BlitzForums, but I doubt that's getting anywhere.
And, the game runs fine. Even though this computer (and that I just learned) doesn't have DirectX12, but DirectX11. And, like I said, it runs fine. I also tested this with a lot of my friends on Skype, I can give you all the test information in a quick format, just PM me.
I've even got a friend to get a Spectre PC, which HAS DirectX12, and it runs perfectly.