I have not seen a single Marxist make this claim. Deng wasn't pro-billionaire, but wished to return to a Marxist analysis of the PRC's economy. It had taken on an ultraleft character and was unstable, they had socialized more than they should have with their level of productive forces, and have consistently been working their way back to that level of socialization now that the Socialist Market Economy has proven wildly successful. Without doing so, extreme poverty could not have been eradicated like it has been.