The reason is plain.

Rousseau's idea exactly fitted in with the political traditions and institutions of the country.

It was more easily and directly compatible than was the contending idea, with that temper and set of men's minds which tradition and institutions had fixed so disastrously deep in the national character.
The crisis of 1758-59, then, is a date of the highest importance.

It marks a collision between the old principle of Lewis XIV., of the Bartholomew Massacre, of the revocation of the Edict of Nantes, and the new rationalistic principle of spiritual emancipation.

The old principle was decrepit, it was no longer able to maintain itself; the hounds were furious, but their fury was toothless.