Yeah, but in this case the conversation is on a marine biology site between marine biologists and the distinction between arm and tentacle is fundamentally meaningful to the conversation.
I agree that the distinction is meaningful, but I suppose I disagree that it is safe to assume that everyone on HN has the same outlook towards the issue — we are not all developers, nor are we all involved in Open Source proper, nor do we all have the same background. In other words: we are not all marine biologists from the same school, I don't think.
I'd suggest that forums like this are good at being specific about terminology, and rigorous about its application.
In other words you, and others, may have used Open Source incorrectly in the past, and may learn from this thread so you don't I the future.
Perhaps your analogy would better apply to Open Source versus Free Software. That's more akin to octopus and squid. Open Source to commercial is more like talking about tentacles when describing a whale.
