"Why would you post it if you think it's crap?"
For money. Buy a bot vote, or self vote, and you have earned rewards.
There is a common perception that self voting is scamming.
In August 2017 the two highest paid authors on Steemit were @mindhunter, and @tamim. @mindhunter paid for all of @snowflake's upvotes, and @tamim just upvoted verses from the Koran he posted.
So, self voting, as does buying votes, associates one with scammers, in many eyes.