It is a bad thing for @blocktrades to self-vote here because it takes rewards from potential new users. @blocktrades, while a good witness, received over 8,000,000 vesting shares from the steemit company on 3/31/2016 and 4/1/2016. To vote for their own post is to use these given shares to award themselves hundreds of dollars at the expense of potential user base.
Even for @blocktrades, giving one's self an award is arguably legitimate in some cases, like for an essay or investigative piece, but a witness update adds very little to the value of steem content. A witness update has limited relevance to most potential users and, like @berniesanders mentions, is merely a justification for earnings elsewhere.
Thanks for a long explanation :)@steemed
To sum it up:
Correct?
I don't agree with the blanket statement, and that isn't what @steemed said either. Indeed one of the benefits of SP, including owning a lot of it, is being able to promote your own posts.
The issue specifically is generating large rewards on a witness report that is already reporting on the process of earning rewards as a witness. It is unnecessary and effectively a form of double dipping.
In fact this is one of the reasons I don't make these posts myself. It reminds me of politicians who send out newsletters claiming to tell everyone about service to the community, but in fact are thinly disguised campaign ads. If what you are doing adds value then it ought to be easy for people to identify what it is you are doing without another post specifically advertising it.