Most of the people that I see speaking out against this are usually new and generally don't know how the system works. I would suggest reading the whitepaper to get a better grasp on how Steemit truly works. A lot of people think self-voting is stealing money from the Steemit community.
Another common disparity that I see is how people complain about this fact, but don't care that you can literally buy influence. Is that any more ethical? The designers and developers were smart. They knew these things would happen.
My stats as of this comment:
STEEM Power: 240.6 + 27.6 (delegated)
VESTs: 495,602
RE: Why is it possible to upvote your own post and comments?