I've noticed that French colonies (e.g. Quebec, pop. 60k white french in 1750s) tended to have tiny populations compared to the British (13 colonies, 2.3 million in 1775) and Spanish ones especially, and later in the 19th century they still emigrated less than most Europeans.

English and Scottish colonists of course moved to Australia and Canada and the USA in massive numbers, even after initial colonization (iirc British emigration to Australia peaked in the 1950s even). The Italians, Germans, Irish and Polish also emigrated to the Americas in huge numbers. Italy's diaspora reaches more than 60+ million if you count Brazil, Argentina, USA and Canada. Meanwhile, no such French mass migration seems to exist, even though France in the 1800s suffered some stagnation and fell behind in industrialization. Why did they not immigrate?