Frankly I think that's riddled with errors of fact but the question is interesting. I've stuck an example in the spoiler since it becomes relevant later.:
Why care about specialisation at all? Here's a point of view from The History Boys, a film/play you should definitely have seen by now:
the dubious title of "general studies". I will let you into a little secret, boys. There is no such thing as general studies. General studies is a waste of time. Knowledge is not general, it is specific. And nothing to do with getting on.
Specificity and specialisation are obviously related ideas. But then take the thinkpiece's generic statement:
A country’s education system should prepare its students for life beyond the classroom, which is more complex than directing students down a supposedly ‘chosen’ path.
It's a bit like the Giant Panda. The overly specialised are exposed to changes in the environment and end up being left behind. In the case of ecological specialisation and climate change the consequence is basically extinction... in the case of future life, here, we're probably thinking more along the lines of automation (of which the consequences are, as yet, unclear).
To my way of thinking both points of view are entirely correct. Maclean's fixation on universities is very ambulance at the bottom of the cliff thinking. Education systems in the Western World tend to have everyone from the ages of 5-16 and it'd be quite intolerable if we chose to try and fix a failure to give people a general basis from which they can be flexible and adaptable synthesists (i.e. drawers of knowledge from all their experiences) at universities.
There are two reasons for the aforementioned intolerability. Firstly, tertiary education is the point in the system where we can be about specialisation. Secondly, universities are an aspect of the tertiary sector that tends to be a lot more relevant for some socioeconomic classes than others... it's like having ambulances but only for the middle and upper classes.
So... how to achieve my ideal balance? Well, NZ's got the tertiary bit down to pat. It's specialised but still allows for flexibility and variety (at least in the university sector). It also gets this done before people are in their mid/late twenties, which gives people more time to enjoy the fruits of their labours. On the other hand... Maclean completely glosses over just how specialised people are able to become as college pupils.
For example, I bumped into a friend of mine yesterday who, as I recall, didn't do maths or science beyond year eleven, i.e. 16. I, myself, didn't do any science subjects from the same age. And then we've got what I seem to recall was termed the Asian Five* of calculus, statistics, physics, chemistry and biology... the reverse intense specialisation. Lots of respect for pupil autonomy, to be sure, but perhaps too much? Given that these decisions are effectively made by 15 year olds (if not 14 year olds)??
So, what say ye NSG? Is specialisation a desirable principle in education systems? Is it an age related concept as I suggest? How would you achieve specialisation/ensure it doesn't exist?
*Seems probable... it has an Urban Dictionary entry.