A little later, she came back to that sentence, pointing that it probably did not convey the meaning I intended. As often, I had liberally transposed a French structure into English, hoping for the best. It usually fails, most of the time because of idiomatic reasons, but in this situation I was fairly surprised: there is no such ambiguity taking place here, and in both languages, the logical relationship expressed by the sentence is identical.
The structure "It is not because [Condition], that [Consequence]" signifies that there is no causal link between the Condition and the Consequence. And yet, the meaning conveyed in each language is very different, because of what should be inferred. In English, it would be interpreted as "As this condition does not cause that consequence, it must be another condition that caused it", emphasizing the existence of another explanation for a phenomenon. This form exists also in French, but is not typical. Generally, it is meant as a challenge: "As this condition does not cause that consequence, a different reason will need to be produced in order for the consequence to be accepted as valid".
So when I tell you that "It is not because the point of this post is intricate, that you should give up reading it", when the Englishman in you may be looking for other reasons to give up (style, maybe?), your French side should remind you that really, one should not give up on something only because it is intricate.