Personally, rms doesn't bother me and he's free to do as he pleases, but what annoys me is the people in rms related threads online who act as if the development of FOSS[0] is entirely dependent upon him. There
were a lot of parallel developments in software, which is not a zero sum game.
I find a lot of rms's essays interesting and I regularly use a lot of GNU software, especially emacs. Still, rms is often divisive and counterproductive. We must call it "GNU/Linux"? We must use one of a handful of "totally free distros" instead of even distros like Fedora and Debian? Stallman played a vital early role, but no role was necessary.
If GNU never existed, we wouldn't have emacs/gcc/etc., but there are alternatives and those alternatives would have become more developed over time.[1] Linux would have used the BSD programs instead of the GNU programs or they would have written their own.
(In fact, if Linus never invented Linux, there would still be FreeBSD, NetBSD, and OpenBSD. These are all, as far as I know, less dependent on GNU applications (if at all) and many people in the BSD communities see the GPL as restrictive.[2])
If the FSF never was founded, we wouldn't have the GPL and we might not have gotten copyleft at all, but we would still have BSD, MIT, Apache, etc., licenses. "Free software" is an ideology that is largely dependent on Stallman, but "open source" software is inevitable because of the benefits it provides society.
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While one particular philosophy of freedom and computing were largely driven by rms's writings, the practical benefits of sharing source under a free license are not at all dependent on some broad philosophical goal. It's just more profitable for businesses to not have to pay for software (while at the same time not being "pirates"), to have access to the source code (for patches, even if the upstream refuses them), and so on. I find it hard to imagine a company with lots of servers like Google existing if they had to pay Windows or UNIX license fees (especially if the competitive pressure from Linux and BSD never existed). Software like Apache's httpd would have existed even if rms never wrote anything, in my opinion.
Companies don't care about the freedoms that rms cares about. They care about making money. It just so happens that you make more money in the long run[3] if you don't get forced into overly restrictive terms by a vendor who then locks you into their proprietary technology, continually increasing fees and restrictions over time. Open source software gets major contributions by people who are paid to do this by big corporations who would rather do this than pay for closed source software. It just so happens that the terms allow end users, startups, and so on to benefit from the big businesses who are ultimately acting in their own best interests. If rms had his way, this virtuous circle might not have come about because rms is very much opposed to any sort of compromise at all.[4]
Stallman is the opposite of this sort of pragmatism that is common in the "open source" world. To rms, one ought to act ethically, and anyone who does not do so is essentially evil. At one point, he said that you didn't have to make software for money, you could just be a waiter. (I can't find the source, but it stuck with me.) The implicit assumption behind this statement is that free software is inherently not profitable in the world where Internet distribution makes charging for distribution of free software impractical. In rms's mind, something like GNU would exist even if one could not make money off of it, had to get a day job, and development had to be sponsored by big not-for-profit organizations like the FSF.
It's noble to be this committed to a philosophy, but fortunately the world does not exist as the "worst case scenario" that rms prepared for. The rest of the FOSS world has largely moved beyond this mentality. Companies like IBM and Red Hat sponsor development for, and make money off of, "Linux and open source". They use those terms instead of "GNU/Linux and free software" because the latter are ideologically loaded, and hence have the potential to hurt their businesses by scaring away potential customers.[5] The people who wanted FOSS in the 1990s got creative and found ways[6] to get massive amounts of cash to sponsor their development so that they could get paid to do what they love. Apparently, you can make software without charging directly for copies.[7]
So I can see other reasons why people active in FOSS would want to not be associated with rms: his complete hostility toward "open source", major Linux distributions, the common use of the term "Linux" instead of "GNU/Linux", the complete lack of the ability to compromise, focus on philosophy and politics over code, etc. If people associate all of the open source movement like rms[8], it could scare away some who would otherwise contribute and help make the world a better place. The useful contributions rms made was his source code (such as GNU emacs) and he did make many useful contributions in the past, but if his ideologies scare off someone from making major source code contributions, then now he's being counterproductive. It doesn't matter how notable his name/initials are if he's making a very public mistake. In the end, all that matters in the FOSS world is the source code.
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[0] FOSS means "Free and Open Source Software" and is a compromise term between "free software" fanatics and those who prefer the term "open source". All three terms are largely equivalent in meaning, but have different ideologies attached.
[1] I think one of the appeals of FOSS is that there is no one leader, no one ideology, no one organization or company, and so on. There is not even just one program for any given niche, there tends to be at least two. Often the alternatives to a given program are inferior in some way, but if the major program they are alternative to never existed, they probably would have been made more capable or forked at some point. (Or another program would have been written from scratch to fill the niche.)
[2] Even the so-called "permissive" licenses are restrictive when compared to the WTFPL. :-P
[3] It's not surprising that contemporary big businesses care about profit. It is surprising that some pay attention to their long run interests! :-P
[4] If you don't believe me (and this very article that's being linked to implies the same thing), see the GPLv3 controversy and also note that the Linux kernel is still under the GPLv2.
[5] If you're making money, the term "free software" is misleading. Also, the term is not unambiguous in English: Google it and you'll find a lot of freeware. It would also be confusing for a company like Red Hat to "charge for free software". "Freedom Software" probably would have made more sense than "free software".
[6] One of the compromises they made was dropping "free software" for "open source" and rms never forgave them.
[7] The ease of distribution and copying that broadband Internet provides should encourage other industries to find ways to make money without charging for copies, as well. Music, movies, books, and so on, probably have ways to make money without the traditional "charging for copies" model. Also note that if you do not charge for individual copies of your software, making all or most of your source code available under an open source license is probably a great cost-reducing technique that just about everyone should use. Sites like reddit have source code available on Github, and they benefit from it because the value for reddit is the domain "reddit.com" and the posts located there, not the software that runs it.
[8] Very few people would want to live in as pure of a free software environment as rms does. I personally don't know how he can get any work done on a tiny netbook. I use two 1080p 24 inch monitors.