It should not be a "cut Codes" debate it should be an "alter the codes to make sense.
As an example:
The Diminishing Returns of Adding More Insulation
https://www.energyvanguard.com/blog/76941/The-Diminishing-Returns-of-Adding-More-Insulation
Adding any insulation to uninsulated homes can save more energy than adding more insulation to already-insulated homes.
Too much is never enough
The debate over how much insulation to use is an important one. There's no clear-cut answer. I can't tell you, "Use this much in climate zone 4 and this much in climate zone 5" because there are multiple variables involved. Here are the main ones:
Climate zone
Type of heating and cooling system
Fuel used for heating
Utility costs
Photovoltaic (solar electric) system costs
Comfort
Your interests and goals - utility bills, carbon footprint...
Whether you're trying to reduce power plant emissions or just save money, at a certain point, it becomes wiser to stop with the insulation and spend your money on the stuff that, dollar for dollar, will yield better results.