This type of power curve would also lead to increased wear on a some pretty expensive drivetrain components, so either the manufacturer has to greatly increase vehicle cost to cover for more resilient parts, or sell something that will tank the public's perception of the reliability of their brand.
Aftermarket pure software tunes can unlock some ridiculous amounts of horsepower and torque on modern cars, but expect your axles, brakes, suspension, or transmission components to need replacement much more frequently.