Selfvoting is a controversial issue.
In the past I've seen several discussions about this and I've seen that most users who have a large amount of HP either by their own stake or by delegation from other people are against this.
However, for some time now I've seen several accounts self-voting and no one talks about it.

If you don't value your own posts by selfvoting then why should others?

This sentence doesn't make any sense, as we write to share something with others and they vote for our posts if they think that somehow the content is quality and adds something to them.

I'm not from the time of creating the blurt and I've never used it.
However, one thing I do know is that they remove the downvote feature but end up censoring by putting accounts they don't like on a list.