Willy in Death of a Salesman feels contemptuous of people who work with their hands. To him, the American dream is one of making easy money. For example, he admires and idealizes Dave Singleman, a popular and successful salesman. Singleman, in Willy's mind, is admirable because he could sit in a hotel room in his green velvet slippers making phone calls and watching the money roll in: the very opposite of working with his hands. Willy says of Dave:

He died the death of a salesman, in his green velvet slippers.

The velvet slippers represent the easy prosperity of living by one's sparkling personality and ability to sell that Willy aspires to. He says of Biff working in farming:

How can he find himself on a farm? Is that a life? A farmhand?

Willy's attitude that working with one's hands in honest labor is the wrong path, one for losers, has left Biff confused. Biff tells Happy that he likes farming and would like to own his own ranch, trying to get Happy to go in with him on that dream. Biff says:

Men built like us should be working out in the open.

Much of the play centers on Willy pursuing a career he is not well suited for and pushing Biff to do the same. Biff breaks free as he starts living his own life.