Why a computer expect to receive responses when it broadcast an ARP request?
Response will be acquired only from the machine for that request is being sent not for the other machines upon the network.
An ARP (Address Resolution Protocol) request message is put in a  hardware frame and broadcast to all computer upon the network. All  computers receive the request and examine the IP address. The computer  mentioned into the request sends a response, each other computer process  and discard the request without sending a reply.