Responsibilities align with funding and ownership. Steem was for better or worse launched on a largely centralized economic model with Steemit (both the company entity and its team/founders) starting out by assigning themselves 80% of the stake (they have less now, but still a huge percentage).

Even what we refer to as 'whales' are comparatively tiny, generally 1/2-3%, most at the lower end of the range. This is both a funding and a governance issue. Since Steemit and its founders never locked their stake into a non-voting account (as was once considered, and a feature even implemented, by them, in a hardfork to enable it), everyone operates under the assumption that Steemit and its team can unilaterally override outside stakeholder/witness voting at any time. As a result, no one feels safe or justified in investing resources in anything other than letting Steemit set the priorities and following along.

Anyway, yes, I agree on literally devolving responsibilities, but it isn't quite as simple as just telling other people to do it without also considering funding and governance.