I believe that most Canadians (rightly or wrongly) would probably support further increases in debt if that money was used to reduce some of the many social problems that we have in Canada and if it was not tied into higher taxes and user fees.  
Unfortunately, it seems that the policy is to expand the size of government, to increase taxes, and to spend millions of dollars on new programs to support the disadvantaged in other countries while ignoring those in need in Canada. 
As with all polls, the answer received depends entirely on the questions asked and the manner in which they are framed. The choices here appear to have been the more extreme option to balance the budget (presumably at the expense of existing programs and/or tax increases) or to allow the debt to grow providing that it does not increase the ratio between debt and GDP. 
Clearly those are not the only choices and the vast majority would have chosen something in the middle - a result that the pollster did not want.