I think that sponsord themes should continue to be allowed on wordpress.org. But, like others have said, there should be some clear disclosure that a given theme contains sponsored links, and it should be easy to remove them.
I suppose the reason that this debate seems to be getting so heated is that it's desingers motives, not actions, that are really under discussion.
I'm sure that many of the designers releasing sponsored themes, would do so without the sponsored links if they could afford to, but this is (part of) a living for some.
Then there are others, who may feel that the sponsor money is an incentive to create more appealing themes. I'm not at all saying that sponsored themes are better than unsponsored ones (or vice versa). But for some people, financial gain is an incentive to innnovate. Which can only be a good thing for the community.
There are risks associated with sponsored themes, and I think that WP.org has to make bloggers aware of those risks. But I don't think that the risks sufficiently offset the concequences of sponsored themes being excluded from the site.