I think you need a bit of remedial math training, starting (perhaps) with simple arithmetic.  If they obtain most of their revenue from taxes, and if they have a much bigger surplus than they expected, then their ability to forecast and plan is monumentally flawed.
As far as NDP governments go, across Canada they have been (by and large) MORE fiscally adept than their so-called "conservative" opponents, as just a few moment's research would teach you.  I don't expect you to believe this, because I think you are entirely closed-minded about the subject.  As a result, I don't think we can have a rational, adult conversation about this.