What “deciders”, in the immortal words of George Dubya Bush, do.
Agenda-setting only lasts so long. Sooner or later a decision on what (if any) policy to pursue has to be be made. There will be winners and losers (though of course, those who think they will win may not, and vice versa).
The venue in which the decision is made matters, and the costs attached to the making of the decision also matters. And the (perceived) reversibility of the decision ALSO matters. Lots of things matter…