Fenier, two points:

1. Though there's no denying that mobile is on the ascendency & works fine for many (maybe most?) types of apps, the idea of people viewing work on art sites like Renderosity on a tiny phone screen seems absurd & so designing the site for that type of device makes no sense. Tablets are a bare minimum & I personally don't use my tablet for Renderosity at all due both to size & quality of image (though certainly I could get a better quality of image by paying more & quality will likely continue to improve). No matter how popular mobile devices become, there is no reason why people would subject themselves to their size limitations in their homes.

2. Rather than abandoning home users for mobile users, doesn't it make more sense for sites to either design for both or offer alternate versions? More upfront work to do that, but a good long term investment.

Don't think it makes sense to have a long debate about this here, I don't think it's the right forum for it, but I did want to at least respond to the idea that you seemed to be proposing that Renderosity sacrifice it's home users at the altar of mobile users.