Scarcity addresses material welfare; plenty addresses spiritual welfare. We need to nourish not only our material welfare in terms of maximizing the utility of the things we claim as private property; we also need to nourish our spiritual welfare in terms of enhancing our character by virtue of how we contribute to the collective store of value.
Plenty that stays static rots, and it rots the character of the one who keeps it for himself. Plus, it not only rots itself, it not only rots the character of the miser, it also rots the character of the collective in which the miser wields power.
The motivation for excretion is to avoid the injury to one's character of keeping that which we have acquired by grace.
The antidote to the corrosion of greed is justice as deservedness.