The ideology behind the extremely contemporary belief amongst brits that "s" is a British spelling is quite strange to me.
z is the British spelling and always has been, s is French and was lifted from French. And made wide-spread by British newspapers in the 60s+.
What is interesting in this case is this author goes all the way back to "connexion" without realising that contemporary to that spelling would be "specialize"
It’s not as clear cut as you make out. There are some specific verbs that should always take the ‘s’ in British English – for example, analyse (in American English, analyze). And then there are verbs that even in American English should always take the ‘s’, like revise and exercise.
I guess its mostly just amusing that cosmopolitans who are keen to appear "at home with everyone" display the same cultural parochialism as everyone else -- namely even doubling down on historical French spelling (over historical English) simply to avoid association with the US.
Similarly, of course, the scottish adopt historical englishisms; and so on, and so on.
With `z` however it's a project of those who'd claim to be above such.
There seems to be a perception in some that in cases where s and z are both officially valid (most of the time), that z is a vulgar Americanism (nasty pointy letter with a harsh sound, both of which stand out compared to the more refined smooth shape & sound of our lovely s!), when, as you point out, z is historically more correct in “proper” English. I don't think it is that they see s as english-english as such, but that they see z as american-english so go with s as an act of identity preservation.
I prefer -ise over -ize, I'm not sure why, maybe it fits better with how I pronounce/emphasise things when speaking. Though it isn't the case that either is more right in modern English: while -ize predates -ise, for about half a millennium it has been the case that both are valid so it is just down to preference.
Which ever you pick, just be consistent. There are some cases where one is considered valid and which one varies by variant of English, such as analyse/analyze, which is probably part of where the s-is-English comes from – applying a specific exception widely as if it were a rule.
There are a few things that many are convinced of about English which turn out to be quite false: the singular “they” being another one that has caused much discussion in recent years, or the not-splitting-infinitives thing which some are still determined to boldly hold on to.
According to Wikipedia[0], using "ise" is still the British spelling, as well as Australian spelling. However, the Oxford spelling of these words are using "ize".
After a customary search, I can't seem to find any sources that suggest using "ise" might be French, and made popular by British newspapers, besides the below Wikipedia article claiming newspapers using the "ise" spelling, instead of "ize". I'd love to see some sources on this if you have any.
I grew up in Britain, and have been spelling using the "ise" version, but since I've started working for a US company, I've started using "ize" everywhere since it's just easier. In addition, it's still accurate British, when using the Oxford spelling. Although, it did take me a while to get accustomed to changing my writing.
I've always understood the "rule" to be Greek-origin words take 'ize' and Latin-origin words take 'ise'. Personally I would rather have one or the other consistently.
I use 'ise' in all cases by default, but if I know my audience is American I use 'ize'. I'm not precious about it.
The z spelling is influenced by Greek, I believe. I think it's fair to say -ise is characteristically British, since it's widely used here and not in the U.S.
z is the British spelling and always has been, s is French and was lifted from French. And made wide-spread by British newspapers in the 60s+.
What is interesting in this case is this author goes all the way back to "connexion" without realising that contemporary to that spelling would be "specialize"