If RMS had only made the GPL a "right to reverse-engineer" license, things could've been very different now. By necessity, knowledge of RE will become more pervasive and tools developed at a faster rate. For the sake of example, I'll call this the "RPL" license. Those who RPL-license but don't release source will just have others produce and release the source for them anyway. People might be RE'ing commercial binaries more often, to see if they contain any code similar to RPL'd ones - and the best part of this is that while differences in source code can be large, compilers tend to make very differently styled source code produce almost identical binary output. Making it much harder to tell apart proprietary and RPL'd binaries means that instead of GPL being "viral" at the source code level, RPL is "viral" at the binary level.
Look at all the big open-source projects out there which are slowly taking freedom away from users like Android, Chromium, Firefox, and even some Linux distros. Open-source does not mean freedom. Then look at all the closed-source but public-domain software, of which there is too many to name. Closed source does not mean a lack of freedom.
Imagine if, when RMS was faced without the source code for that printer software, he RE'd it anyway to patch in the features he wanted, then founded GNU on that... but instead his narrow academic mind conditioned him to think that binaries were mysterious things output by a compiler and supposed completely impossible to modify. Opening the file in a disassembler or editor is far easier than begging for the source code and going through all the stupid legal bureaucracy. If he got into legal trouble for doing that, it would send an even better message - imagine seeing news of being arrested or sued for
improving existing software! "It is better to ask for forgiveness than permission."
This is the only true freedom to study and modify software, and you already have it, even if not legally, just by owning a general-purpose computer. So it's somewhat ironic that RMS even mentioned it in
https://www.gnu.org/philosophy/right-to-read.html , but in his narrow-minded effort to concentrate on source code missed seeing this powerful concept completely.
Now we're seeing all these locked-down DRM'd platforms proliferate and all he and his GNUdiots can scream about is the goddamn source code?
"
Source? We don't need no stinkin' source!"