The simple way I see as to why the vote turned out the way it did is simply that we do as a country seem to be in better shape than we were 5 years ago. Now how much that actually has to do with the ConDem's is debatable, the economy was showing signs of improvement as they came into power so a lot of it in the most part has just happened anyway.
The simple reason I voted Conservative is simply based upon this reality, so what would be the purpose of changing the government back to Labour and risk what is happening to the economy, which is the subject I feel the most strongly about?
Plus I have never really trusted Labour since Tony Blair went to war and Milliband comes across as a total tool.