Simply not true.
I worked there as a contractor during that period. It was fairly grim, but don't ascribe to malice what can be explained by incompetence for example. It was also a better outcome than for my previous client, Lehman Brothers, in that it wasn't dropped on the floor for no particularly good reason, throwing away even more value and confidence.
Please don't quote conspiracy theories in the absence of any actual facts.
It is true that reducing the global markets operation is stated policy, but that is about reducing risk and making RBS more viable, not to "run [it] into the ground".