That's what reducing externalities looks like.
You're implying all businesses have the same externalities. Because right now they all pay the same tax rate regardless of what they do. Really reducing externalities would look more like beef being $15/pound and air travel costing double what it does now, but solar power being cheaper than coal and locally produced goods being more competitive because of lower transportation costs.
You say taxes are the cost of operation. Okay, let's tax according the costs of operation. Not a flat rate regardless of what the true cost of operation is.