This "ideological purity" didn't come out of nothing, it came out of the very practical issue of who is in control. People forget that RMS came up with the whole thing because he wanted to fix a broken printer and was denied the source code that could help him fix the issue.

He wasn't siting in some ivory tower coming up with abstract philosophical questions, he was in some lab and had an actual practical problem he wanted to fix.

Ideological purity is a valuable thing. Look at Minix, hell, even look at the BSDs today. These are projects that have collapsed because of their feature obsession and ignorance of ideology. The differentiation of ideology is what makes free software uniquely successful - it is the feature.

> Mainstream users see Free Software people as irrelevant kooks, and thus easy to dismiss, which is why Free Software has so utterly failed as a movement.

Mainstream users don't think about Free Software at all. They certainly use it though. They rely on it, to provide and maintain the runtime their cell phone and iPad and router all depend on. It probably runs an RTOS on their grandpa's CPAP machine, it probably occupies the DVR for their cable TV and it's likely running on their games console and personal computer, too.

Free software is even more inescapable than proprietary software. If users cared enough to understand the difference, you and I both know they would accuse the businesses of being the irrelevant kooks. Not a single "maintream user" I know would defend Apple or Google or Microsoft's business practices as software companies. No one.

> I'm sure flat-earthers feel that my belief that earth is an oblate spheroid is peculiar, too. Of what relevance is that to anyone?

As the other comment suggested, this is both an insincere response and one where you are the flat earther here. The FSF has reasons that they hold the principles they do, and you haven't refuted any of their ideology. You are the guy lambasting Gallileo, and when Gallileo asks you why heliocentrism offends you, you are replying "because the mainstream clergy sees you as kooks." It's not a response at all.

> The emacs developers don't even understand how large chunks of emacs work

Nobody is so stupid that we expect every kernel dev to understand the whole of the kernel. It's folly, and not what I was asking anyways. Nobody at Apple understands how the entirety of iOS works either, but that's not an implication that it's inherently insecure. What makes the FSF balk at Apple is the inaccountability. The lack of reason associated with their statements asserting the privacy and security of a system that sues it's auditors.

If you have a more reasonable heuristic to suggest, I'm all ears.

(The Earth being round doesn't directly matter in practice to most people. It does have inevitable consequences though.)

Or perhaps a better example is anthropogenic climate change : here too the implications are extremely inconvenient for most people, so denial is rampant.