I don't think up-voting your own post or bot voting makes you try any less. personally i save my bot votes for posts that i've worked hard on and i want to see succeed. for example I wrote a benefit post for someone, and i bot voted the heck out of it, because it was a gift. for many, bot voting is merely a form of investment. You invest one sbd then receive two; this is a good investment, especially for a minnow who hasn't gotten much notice yet or who has little to invest into buying steem.

as for self plagiarism, it's done all the time. i've seen magazine articles posted in multiple places on line, or recycled years later as a slightly different article. if it's ok for professional writers to do this, why should it not be ok on steemit? imho i think it is ethical to say something. however many posts that were created when the author was new to steemit and earned pennies the first time around do deserve a second shot. especially if the post has quality work.

authors who post the same thing several times fall into two categories; noobs who havent caught on, or those who re-post in order to make money and dont give a shit because its just business to them. these people tend to mutually upvote friends for profit. you won't stop that kind of crap, so my advice is to ignore it.