I respect your opinion and your efforts on behalf of the community fighting spam and plagiarism, but I disagree on this.
Just because you don't like a business model doesn't mean it's a bad one - I hate big oil - but it's a great business model. The votes belong to the users, not me and not you, and if they are happy to pay for a premium service with that vote, I don't see the problem. The Steemit userbase are subsidizing the business to about the same degree as your original comment, and to the same degree as any other comment/post/service running on Steemit. In fact, I think comment voting is the biggest unnecessary drain on the rewards pool, it should be replaced with a tipping system.
You refer to subsidies and socialization, but at the end of the day, this is nothing of the sort: it is a free market enterprise. If there wasn't a demand for the service, it wouldn't exist.
I did try to discuss this with you on steemit.chat dm yesterday and I'm happy to continue there if you like, though I'm not sure if we'll be able to come to any sort of consensus.