I have never had a problem with people upvoting their posts. If it was not allowed on steemit, the option would not be available. As a small minnow, just starting out, upvoting your own comments might get you another 1 thenth of a cent. I'm not sure where the "upvoting your own comments" goes from self help to "raping the reward pool". It's an arbitrary decision, depending on who you ask. I haven't upvoted one of my own comments in a while, but I did when I was first starting. Sometimes it was about the only rewards that I got from the post.