I think in a fair and just Steemit world, this would be a good addition. However, we don't live in a fair and just Steemit world. We currently live in a Steemit world where newbies are being favored over minnows who have worked hard for their position. These minnows had to fight their way up and now have to fight to stay visible. One way of doing that is to upvote their own post, so it looks more appealing to others (the alternative is no one opens their posts anymore).
This might sound a bit sour, but it's what I've noticed a lot lately and it's what I hear about a lot from others aswell. Adding such an option would only serve to ignore these older members even more.