Upgrading attic insulation is a VERY popular energy-saving improvement because more energy (and money!) is lost through the attic than through any other part of the house.
What makes matters worse is improperly or poorly installing inadequate attic insulation. Existing attic insulation in many homes may be as minimal as R-19– which pales in comparison to the recommended R-value!
Going through a cold winter with so little insulation is like wearing a t-shirt in a snowstorm. What your house really needs is the equivalent of a thick down-filled parka.