Capitalism is nothing but an economic system where you own the means to production. There is no inherent morality.
Nobody has an issue with you making choices and voting with your dollars. The issue is forcing those choices on everyone else (as in a business, especially as a non-owner) through your own interpretation of morality.
It refers to "you" vs the state. You create a factory or a business or a new patent and you're responsible. You gain the profits or suffer the losses and nobody else can take it from you.
Workers are obviously not business owners, but they do own their own labor and are free to take whatever job they want, not be assigned to it from some central authority.