What use is the semicolon?

Apparently, according to some French writers, not much – according to this article, very few modern French writers use it, and the decline in its use is due to the invasion of British usages which are "too direct" to make use of the supposed subtlety of the semicolon. The only problem is that many English writers themselves make use of it – having just gone over my own main page I find several of them.

How is the semicolon too subtle for English, then? The purpose of it is to demonstrate a connection between one phrase and another, both of which qualify as sentences in themselves, that is stronger than that between two separate sentences. Perhaps that's subtle, but not too subtle that it's beyond the reach of anyone who wants to be a serious writer to understand, when it really is a very useful, even important, piece of grammar?

I've long been pretty conservative when it comes to matters of the English language (as here), but I find the attitude of some of those quoted as being against it, both French and English-speaking, rather off-putting. If people don't find it useful in their writing, they are quite at liberty not to use it, but they should not dismiss it as reflecting "a fuzziness of thought" or just that you've been to college. (Actually, I'm pretty sure I used them before I went to college, but I do remember asking my teacher about semicolons when I was 7 or 8 and being told we did not use them in that year.) Do people really hate their English or French teachers that much that they deprive themselves of a way of expressing themselves in writing, let alone want to deprive others?