The self voting is bad for steem, but has major incentives for individual steemians, thats why:
- If other stemians vote for others, than all is great anyways
- If other stemians vote for themselfs, than all is bad but you can do nothing to stop it, just getting what you can by upvoting yourself
It's a "tragedy of the commons". The situation can not be eased by appealing to the conscience of people - they act in their personal interests. It is necessary to change the system so that there is a common cause where most profitable.