Because putting a somewhat-precise resistor inside a connector is not trivial, and would likely double the price of the connector due to the increased complexity of manufacturing.

On the other hand: the resistor itself is basically free, and you are already putting a few dozen of them on your final PCB anyways. Adding one more resistor value barely changes the assembly process.

The people who are willing to skimp on USB-C resistors are definitely not going to splurge on a custom drop-in connector module, so it would not solve any real problem. The resistor-less devices are broken because their manufacturers do not care that they are broken. You can't engineer yourself out of that kind of greed and apathy.