Reason Downvote by @spamminator, why?

I don't understand Hive account@spamminator always comes to my posts and downvotes my posts. is there a clear reason? there is also no notification, is my post plagiarism? but i don't plagiarize. what happened? is it because my account is from the old steemit?

and because Hive account@spamminator came to my post as a result I was also visited by several other downvotes, Hive account@gniksivart Hive account@freebornsociety Hive account@buildawhale

you will also find Hive account@spamminator in my post this one