Sponsors receive many more proposals than they can fund. It may be a question of timing or resources. Do not always assume that something is wrong with the proposal. It is also unusual to receive external funding on your first try. As with many things, persistence is key to success.
The federal government is required to make review results available in a format of their choice. They may agree to a conference call, provide reviewer comments, or send a letter synthesizing the comments. Your OSP staff member can help you with this request although some agencies require that the request come from the Principal Investigator. Private funding sources may or may not have the resources to provide feedback on your proposal and are not required to do so. OSP can also make this request for you.