This issue already been noticed and mentioned by several people. @aneukpineung78 for example mentioned it and added proof and schedules to his posts.

It is already clear toe since months certain people send to me refuse to be in my team simply because they made deals to upvote those they were sent by and know those people never comment and are not into art or creativity.
This happened more than ones.
They play innocent if I directly ask if they made a deal.

If you put the months following together you will notice the trend.

No one stepped in, the corruption is ignored, only the small users in the past has been reprimanded or been broken to the bone for minor acts.

If the same have different functions nothing will change so all that is left to believe is that steemitblog/ the steemit team account is in hands of the same people. For sure this is not Steemit Inc. otherwise they would have acted long ago.

The biggest abusers of this platform, hacking curator accounts included, rovlbbing community incomes, all started new and they receive upvotes.

If things like these happen one can only conclude this is what steemitblog wants and knows about.