Charles W. Calomiris and Stephen Haber made a similar point in a recent EconTalk interview discussing their book Fragile by Design. When the US government wants to promote a populist cause (college, home ownership, farms), it is easier to do so off balance sheet by reducing interest rates rather than giving a straightforward subsidy. Thus, we trade economic risk for a reduced federal deficit.
http://www.econtalk.org/archives/2014/02/calomiris_and_h.htm...