Stallman's goal is not to prohibit proprietary software; but to have a world where most people choose Free Software (whether they're aware of it or not), so that it would be difficult to convince anyone to use proprietary software.
Compare this to our current situation, where everyone's so used to clicking "I Agree" on an EULA screen before they can use a program that many Free Software programs (most famously Firefox) started including such screens, even though there is no requirement to agree to any terms before using them! Of course, there are usually terms related to redistribution and re-use of the code, but that can be done without ever seeing such a screen.
Stallman doesn't disagree with BSD/MIT licenses; he only advocates the GPL as a short-term measure to get to the goal quicker. BSD/MIT code is (usually) a valued contribution, as it lifts everyone up equally; Free Software is lifted, but so is proprietary software since it is trivial for anyone to repackage it as proprietary. That's fine if your goal is to advance the state-of-the-art, give unimpeded access to better security, get your ideas out there, etc. but it doesn't do very much for (or against) the goal of having mostly Free Software.
The only way to go the other way and turn proprietary software into Free Software is by a dedicated effort on the part of the copyright holder (who may be dead!). Hence the playing field is heavily biased in proprietary software's favour, which endangers the mostly-Free goal. The GPL tries to rebalance things by going the other way.
In a mostly-Free world, this bias would (hopefully) be counteracted by the inertia of Free Software, so the GPL would be unnecessary and the more permissive licenses would be a better choice.
Notice that Open Source didn't feature in the paragraphs above, since it's unrelated. That's Stallman's argument: it misses the point. He doesn't say it's intrinsically bad, although it may cause indirect harm to Free Software through distraction and confusion. Of course it also does indirect good, by leading people to Free Software who would never have been exposed to a purely Free Software message.
> Compare this to our current situation, where everyone's so used to clicking "I Agree" on an EULA screen before they can use a program that many Free Software programs (most famously Firefox) started including such screens, even though there is no requirement to agree to any terms before using them!
This is in part due to the fact that for a long time it was difficult to forgo the EULA screen on the Nullsoft Scriptable Install System, which a lot of free software projects were using for their Windows ports.
As a Distributist, though here's where I disagree with at least your characterization of Stallman's views (I don't know for sure what he thinks on corporate control of free software, but I will grant that the FSF acts as if that is actually desirable, by setting the precedence of requiring copyright assignment).
For me the question is about corporate control, rather than end-user access to the code. For this reason I see the following things as harmful:
1. Dual licensing
2. Requiring copyright assignment for contributions.
These things place organizations in control of the software, and they are things less important to more permissive licenses.
Hence my view is that the BSD license is more radically anti-corporate than the GPL.
Compare this to our current situation, where everyone's so used to clicking "I Agree" on an EULA screen before they can use a program that many Free Software programs (most famously Firefox) started including such screens, even though there is no requirement to agree to any terms before using them! Of course, there are usually terms related to redistribution and re-use of the code, but that can be done without ever seeing such a screen.
Stallman doesn't disagree with BSD/MIT licenses; he only advocates the GPL as a short-term measure to get to the goal quicker. BSD/MIT code is (usually) a valued contribution, as it lifts everyone up equally; Free Software is lifted, but so is proprietary software since it is trivial for anyone to repackage it as proprietary. That's fine if your goal is to advance the state-of-the-art, give unimpeded access to better security, get your ideas out there, etc. but it doesn't do very much for (or against) the goal of having mostly Free Software.
The only way to go the other way and turn proprietary software into Free Software is by a dedicated effort on the part of the copyright holder (who may be dead!). Hence the playing field is heavily biased in proprietary software's favour, which endangers the mostly-Free goal. The GPL tries to rebalance things by going the other way.
In a mostly-Free world, this bias would (hopefully) be counteracted by the inertia of Free Software, so the GPL would be unnecessary and the more permissive licenses would be a better choice.
Notice that Open Source didn't feature in the paragraphs above, since it's unrelated. That's Stallman's argument: it misses the point. He doesn't say it's intrinsically bad, although it may cause indirect harm to Free Software through distraction and confusion. Of course it also does indirect good, by leading people to Free Software who would never have been exposed to a purely Free Software message.