Getting back from the basics: What is the role for attention and fronto-parietal circuits in consciousness?

Morsella et al. present a novel theory of consciousness which is more "low-level, circumscribed, counterintuitive, and passive" than previous accounts. There is much to like about this approach. However, what are the explanatory costs associated with these characteristics? In particular, how does this low-level and passive theory accommodate evidence for top-down attention being necessary (but not sufficient) for visual consciousness?