It doesn't matter that you do that or not. It matters that with high enough HP anyone can do it. They don't have to vote only in those that can also give big upvotes back but it's very easy to make connections when you're able to leave $5+ votes on posts.

And retaliation is only possible with a big HP, that's what azircon did to me and several others because we didn't agree with him on discord. And when I gave DVs back I got DVed for life. He gets $20+ in all his posts, and I've yet to see one that deserved those rewards. He gets a few DVs from people he nuked but it doesn't affect the payout in a meaningful way. If he had 1k HP there's no way he would get these votes.