The FCC's approach to regulation of the electromagnetic spectrum is that it is a "common good", i.e. it is rivalrous but non-excludable. In their view, nobody has a right to use the spectrum in the USA. They grant licenses to use it, and they can tell you how to use the spectrum you are licensed to use.
Apparently, there were documented problems with WiFi radios being operated outside of their licensed parameters and interfering with safety critical airport radar systems.
It's probably too late to persuade them to change their minds. The public response to this topic was voluminous. They received way more comments than they usually do, but they still chose this approach.
If you care, you should choose to support hardware vendors that make the effort to separate the WiFi radio from the main system, allowing you to install your own firmware.