Well, what you say is actually related to the truth. Very vaguely related. It's like truth's second counsin's wife's nephew. They met once, in passing, when you had the idea of saying Catalyst on Windows isn't hard to surpass, then never saw each other again. Considering how crass, dismissive and injust what you said was, it's no wonder truth didn't want to see it again. Which is funny, since pretty much everyone, after some thought, seems to think truth has those exact same characteristics.
But I digress. It's not hard to surpass Catalyst on Linux... in OpenGL workloads. Try running an application that uses DirectX in Windows, then compare its performance to OpenGL in Windows, then compare it to Linux. The problem is games are mostly tuned to DirectX, and Catalyst is mostly tuned to those games. Despite AMD's latest efforts, OpenGL on Windows, and for open source games nonetheless, is pretty unimpressively optimized. Even the open radeon driver can surpass Windows. Were a different game, like, say, Left 4 Dead 2 used, you could investigate more throughly, but Phoronix doesn't really do that.
As for nuking a system install due to Catalyst... that's certainly not the case. Hasn't been since at least 2010, I'm afraid. Not that the installer is good or user-friendly, but removing Catalyst is quite a brain-free operation, even if your distribution doesn't provide it already packaged.