The idea that Conservatives are 'fiscally responsible' is probably one of the most enduring myths of modern politics. If you actually pay attention to the balance sheets of Western democracies, Conservative parties have no better of a record than others, and in Countries like Canada their record is down-right abysmal. There are various reasons for this poor record at both the federal and provincial level. One reason is the simple fact that regardless of what Conservatives always tell us, Western economies are subject to the regular booms and busts of Capitalism and there is little or nothing, particularly in a global economy, that individual parties can do. (The best they can actually do is the very opposite or what conservatives do, and that is maintain a proper social safety net so that when recessions do come, the most vulnerable will suffer less of an impact) Another reason that Conservatives have a terrible record on fiscal management is that they just can't help giving away the store, so to speak, to their rich friends and corporations through tax cuts, and grants to those who need them least. Their "trickle-down" economics model was discredited long ago but they still keep doing it because that is their MO and their ideology is basically one of selfishness so why wouldn't they carry that selfishness into their fiscal (mis)management strategy?
However, the most disturbing reason that Conservatives are poor fiscal managers, and this is very much the case for this Government, is that they actually want to send the state broke in order to justify the dismantling of the social programs and the processes of democracy that they hate so much. The fact that Harper brought us to the verge of deficit before the recession hit and that he once wrote (apparently in his Master's Thesis) that running deficits is 'always' a bad idea economically speaking and that politicians only do it for electoral advantage, tells you the whole story. All of this suggests that their mismanagement was at least in part motivated by an intentional desire to more or less bankrupt the state and thereby discredit any social efforts on the part of government.
But of course, as is the case in many things in life, a strategy quickly runs away with itself and one loses track, and what started out as a strategy becomes a habit, and you find yourself buying multimillion dollar fake lakes and useless gazebos which quickly create the optics of ineptitude. So eventually Conservatives get voted out of office and leave others to clean up the mess while they walk away with padded pockets, rich pensions, and hefty bank accounts in the Cayman Islands where they don't need fake lakes.