Because his greed is enormous, and he can't stand that someone else can get upvote outside his circle jerk.

In addition to being a witness (high steady income), he created endless daily automated reports, memes posts, shit-posts... for selfvoting from various accounts. He even making money on downvotes. I just noticed that he compete with an early upvote on curation rewards behind his post! He is pissed now because he can't selfvote with others accounts anymore as before. He blames me for this, and since I upvoted you, he was on the other side. Simple.

Maybe you didn't achieve his level of quality. Just take a closer look what he is doing and learn how to get more votes. Obviously you need to write less and copy more.