The goal is not simply less. The goal is more of the things that count: like time building and enjoying relationships of trust, time for reflection, time for rest, time to heal and dream and worship.
Of course, Hamilton has neglected two possibilities in this brief paragraph. The first is earning less through voluntary pay cuts. However, perhaps this can be regarded as agreeing to perform some of your paid work voluntarily. The second is generosity, in which money earned is not spent but rather given away to those in need. While this may increase the consumption levels of the recipient, this is a good thing if it means their basic needs are now met. However, if it simply means someone else consuming unnecessary luxuries, then while it may have other worthy beneficial outcomes, ecologically it just pushes down one lump in the carpet only for it to reappear elsewhere.