Really? I'm curious what the argument is here. Do they mean it's a modern invention or mostly an imaginary/idealized concept?
I live in Canada having lived in both francophone Quebec and growing up in Ontario I believe there is a strong french identity. One they take serious care in protecting and developing even as expatriates in Canada. This as a result influences personality/psychological traits as well through things like parenting and cultural experience.
A lot of people I knew in Montreal were recent immigrants from France and to me it seemed they equally shared this identity, although they were far less likely to look up to France in a good light. Although many youths leave France to seek opportunity in Canada, and french Canadians may hold an idealized view of France, so that might be why.
This difference between angolophone vs francophone cultures is one of the reasons I had a lot of difficulty living in Montreal. The differences went well beyond language. Similar to the east vs west coast (vs south) dynamic in the US.
Whether or not being so protective of their identity/culture is a positive thing is a another matter (one I believe is self-destructive to an extent). But whether or not it exists is doesn't seem any question in my mind.