So long as you are spreading the votes and not just voting for yourself is see nothing wrong with voting for your own posts. After all it takes a lot of time and effort or investment to get to the point where your own vote counts for much. I rarely do more than one post a day so I feel like this is fair.
I usually don't vote for my own comment unless someone else votes for it first. (Unless I feel like it really adds value to the conversation)
There is a lot of luck involved with how well a post does and it doesn't seem to correlate too well with the level of effort that I've put into it. I figure it is kind of a nice benefit to be able to vote my own post up and get something at least.
Let's say hypothetically that the price of Steem went into three figures. Would it feel right for me then to vote my own content up? ... :D (I can't even answer my own question, lol)
If someone is really acting in a way that is not community minded I think that they don't tend to do too well in the long run and can start attracting flags, so in a way this tends to work out imo.