Think of it this way: because the tsarist system was so unbelievably bad, there was relatively little risk that you could screw it up worse. The basics were not provided for. The feudalistic government had little interest in expanding the economy (so long as they were happy). The Bolsheviks promised not only economic fairness but economic expansion and simply by moving capital from the rich out to the rest of the economy they were able to do it - for a start.
But while economic expansion and economic fairness may ultimately serve the same purpose and may even (ultimately) go hand-in-hand, they are not the same thing. After you've provided for the basics - made the economic decisions that are no-brainers - how do you take the next step?
boddi