I agree. I will say that there is a use-case for vote purchases aside from rewards, which is promotion. As the promoted section here on steemit is hit or miss, in some cases it may be worthwhile to promote your post through the use of purchased votes. For example, if I were to work with a client to promote their product on steemit, I may use some of their advertising dollars to promote one of their posts via purchased votes. Having said that, the ROI there is even sketchier than before, but it's a possible use.
RE: If you buy votes, f**k you.