Charley is a loyal friend to Willy, and desperately wants him to accept reality to allow him to have a real future. They have known each other for a long time, and despite their constant sparring both men know that their relationship is strong.
WILLY [On the verge of tears] : Charley, you’re the only friend I got.
It is a great catastrophe that Willy is unable to accept Charley’s real offer of support but keeps depending on the fantasy of having a job yet taking money from his friend.
WILLY: I can’t work for you, that’s all, don’t ask me why.
Charley accepts the mercurial nature of his friend, and is able to articulate Willy’s tragic demise with sensitivity-
CHARLEY:…Willy was a salesman…He’s a man way out there in the blue, riding on a smile and a shoeshine. And when they start not smiling back – that’s an earthquake.