But then, if we conclude that we must be a BB, there is no reason for the physics of the universe in which this BB exists to be the same as the physics of the universe we experience. Hence, the argument breaks down, because BB are only very likely in the 'simulated universe', but have no reason to be in the 'real universe' (which has no reason to abide by the same laws of physics).
In other words, the assumption that we are a BB, because they are so much more likely, invalidates the argument that BBs are much more likely.
