Good analysis but I would say that Steemit cannot replace Quora. I've written on this topic previously and recently changed my views somewhat. The key thing is as you said, the bandwagon effect of Steemit in anticipation for rewards. That is a very dangerous way of incentivizing knowledge. Nassim Taleb has written much about the value of risk being involved in the quest for knowledge. Risk less peer review of answers only leads to more problems. The bandwagon is already bad as it is on Quora and the Steemit incentive structure is even worse. That said, I do have hope for the success of Steemit, but its identity is else where.