FOSS is very close to First Amendment arguments of the form "you can print out the source code and publish it like a book; distribution of software code is analogous to distributing a book". This is what saved FOSS cryptography (probably) back in the PGP/crypto wars era [0]. When you start charging money for the commercial use of software, the commercial-service part isn't simply an expressive-speech act, and drags in a whole suite of regulatory options. But publishing a software algorithm, that's not attached to something resembling a commercial business service—that's a purely expressive act, and protected.

[0] https://en.wikipedia.org/wiki/Phil_Zimmermann#Arms_Export_Co...