It's not right for someone to sell a service, accept money for it, and then purposefully not deliver the service. That is just stealing whether it's for vote selling on Steem or anything else. It's also not just as simple as asking the vote selling services to refund the payment for any removed votes, because while they can remove the vote they cannot get back the voting power that was used.

The whole way Steem is set up to work is that if the community feels that a post has more rewards than it should, they can downvote it. The problem was that in the past it cost money (in the form of reduced voting power) to downvote. With HF21, that will change, and it presents an opportunity to make changes to how vote buying and selling works on the platform.

It's very easy to yell at bot owners to "have standards", but people have been yelling about that for years and it will never happen. With the free downvotes we now have the opportunity to solve the problem from a different angle - take away the profit from shitposting and buying votes - so then it won't even matter if the bots have "standards" or not.

So, yes, I do think you and I and everyone who cares should use their new free downvote to downvote shitposts upvoted by bots. It only takes a relatively small amount of downvotes to counter all the profit made from buying votes, and once "shitposters" stop making money buying votes they will stop altogether and all will be well with the world.