Why does Dominic betray Barb's trust in the novel, The Wise Women?

After Dominic learned that Barb had not given Clementine his number as he asked her to do years before, he rebelled by throwing away her idea of compromising with the community on The Point. Dominic told Barb that he had decided to lease the area intended for an art space and cooking school to Whole Foods because he will make so much more money on that lease.