A trustee's responsibility is to creditors. While directing the disposition of assets, a trustee may judge that a secondary offer better serves the creditors.

In this case, the creditors are the Sandy Hook families who were wronged by Jones. It is my understanding that they had a hand in The Onion's offer. I suspect they signaled a desire for this sale to the trustee - but that is just a guess.

source:prepped personal bankruptcy cases for a couple of years