I could be wrong (although I rarely am), but I believe the Britons are ‘subjects’, not cititzens.
I presume you’re talking about ‘How do you become a dual citizen?’ (It helps a lot if you link to the column.)
In any case, it’s not the case that there is no such thing as a British citizen. ‘British subjects’ used to be far more common than now, due to changes in the legal recognition of various catagories of people.
Checking in Wikipedia, in the article on “British subject”, I find that I was a British subject under UK law until 1983, and under Australian law until 1987. (My other big citizenship change was that I automatically became an Australian citizen in 1949, without knowing it (I was aged 3 at the time, and living in England).)
For Og’s sake don’t tell the Scots that. It took a lot of Wars and an act of Parliament to get them under control and you’re going to set them off again.
Welcome to the SDMB, Bobthecat. If the current Staff Report ‘How do you become a dual citizen?’ is the item you’re commenting on, please let me know. Staff Reports are written by Cecil’s assistants, not by Cecil himself. If that’s the one, I’ll move this thread to the appropriate forum, Comments on Staff Reports.
Cecil himself has used the expression “British citizen” at least once, a few years back: http://www.straightdope.com/columns/040806.html If that’s the one you’re commenting on, this thread belongs right here.
I like to think of it as a highly-leveraged reverse takeover 
Considering the role the Darien Scheme (a 1695-1699 get-rich-quick plan involving selling woolen underwear to the natives of Panama) and the resulting thorough Enronification of the Scottish economy played in the circumstances leading up to the 1707 Acts of Union – 'tain’t all that funny.
Not while diagonals are in play
“cititzen”?
Would that be a Page 3 girl?
Well, no shit John - at least some of us Scots retain a sense of humour.
There’s a new kid in town, Tractor-boy!
Pollockshaws West!
Cowcaddens!!!
Rarely, but… here, you are.
In 1981, Parliament passed the British Nationality Act. It was a vast overhaul of the previous law concerning citizenship, and inter alia drastically reduced the number of “British subjects” in the world. The linked Wikipedia article does a fine job of explaining the evolution from “British subject” (pre-1949) to “Citizen of the United Kingdom and Colonies” to either British citizen or citizen of one of the Commonwealth countries in 1983.
Suffice to say that there are a very very few British subjects left, but it is impossible for any new subjects to be born, so there will come a point when there are no more British subjects, period.