Absolutely phenomenal, why are we paying for duplicate school services, paying for the same management roles, etc.
The answer, originally lies in the Constitution and minority rights. When the country was founded (1867) the political deal reached was essentially one between 'French' and English' and, at the time, that also meant between Catholic and Protestant respectively.
The 'public' school system was, in point of fact, protestant. People tend to forget that. But even when I was a kid (we're talking the 80s here), you recited the Lord's Prayer every single day following O'Canada.
Bible verses were standard material for public speaking. By that time, the schools weren't even thought of as protestant, but those were vestiges of an earlier era yet to be disposed of........
When the constitutional deal was made, outside of a small Irish minority, the assumption was that Catholic schools would be the French Schools and Public/Protestant schools the English Schools.
It was only later, due to extensive immigration from non-French, Catholic countries (notably Italy) that we saw Catholic schools in English Canada become a more significant force, in English education.
Likewise, the secularization of Quebec in the 1960s led to the idea that French wasn't merely for the Catholics, and that was also driven by the exodus of Quebecers into Toronto in the FLQ/PLQ era.
Most of those were anglos, but not all, but many/most spoke French and wanted their kids to retain that ability.
Hence a system now out of step w/the times.
It's such a waste of our tax money.
Is is.