Sentence Construction: "Just Because ...... Does Not Mean"

I've already found an entry on this here.

However, it does not solve my problem:

I just read an entry on "cross platform" from Wikipedia, in which it wrote:

Just because a particular operating system may run on different computer architectures, that does not mean that the software written for that operating system will automatically work on all architectures that the operating system supports.

I have seen sentence construction "Just because...does not mean" quite often, but it was my first time to notice that the word "that" or "it" could be present in the construction as well (e.g., "Just because..., that/it does not mean").

Could someone please explain which usage is correct?

Solution 1:

My analysis of it is that neither "that" nor "it" belongs in the sentence, and neither does the comma.

Usually when you use the "just because X does not mean Y" construct, the "X" part is so long that there's the desire to stick in a "that" or an "it" to reiterate that you're referring back to an actual noun. Otherwise it feels like the back half of the sentence floats without a noun. Note also that the comma doesn't belong there either: That's a verbal tic, a pause for breath, not a grammatical construct.

(EDIT: Just to be clear on this, I think both the "that/it" and the comma are the result of writing as though the writer were speaking. In speech it might feel necessary to breathe and then restart the half-completed sentence with "that" so that you have a subject noun.)

However, just because the forward part of the "just because...does not mean" sentence is so ridiculously long and convoluted that nobody in their right mind could ever possibly follow it and still have the original piece of the structure in their heads does not mean that people can't actually follow it if they're accustomed to the "does not mean" tag on the end.

As a caveat, I'm not really sure how the grammar fits together for this kind of construct. If I were trying to produce something in idealized English grammar, I think I'd say "X may be true, but that does not mean that Y is also true". In a case like that, the "that" is clearly needed as the subject noun of "does not mean".

Solution 2:

The problem, as I see it, lies with the use of because. Let’s take a simpler sentence:

Just because you’ve passed an exam, (that) doesn’t mean you know everything about the subject.

If we leave out the that, there’s still a problem which first has to be resolved. We’re asking the clause Just . . . exam to be the subject of doesn’t mean. That's awkward, and I'm not sure I can analyze it adequately, but it's perhaps best understood by reading the clause as if it were in quotation marks. The insertion of it or that is a relatively trivial matter, being just a different way of packaging the information in the way jprete has so well described. The OED has at least two citations showing the construction:

Just because they put a new, refined blah-blah diesel engine in, it doesn't mean it is going to set the world alight.

and

Just because a drug is sold at the chemist, that doesn't mean it's risk-free.