Why do people continue to pay PDI (Pre Delivery Inspection)

I am astounded these days that people will blindly accept the bs charge
of the PDI. The car comes from the factory already inspected and ready
to go, except for the cleaning, removing of protective film, adding
license plate holders, adjusting the clock, etc.

Because people have blindly accepted paying this fee, dealers are
really cocky about it and will tell you to take a hike if you don't pay
the PDI.

Why don't people stand-up to the dealer? Heck, with this kind of
attitude, we'll be paying list price for our new cars someday.