Comment by londons_explore

Hardware schematics and full source code doesn't tell you everything about how a piece of hardware is made either.

How was the hardware tested? How was it calibrated? How was it assembled?

An ingredients list tells 90% of the story about how food is made, and in most cases an expert could guess the remaining 10% to get a decent result. Likewise, hardware design+code tells 90% and an expert could figure out the remaining 10%.

The government could totally require all consumer products have published source code. (published source code != a license for others to use the code)