Why does France think the French language is soooo important?

I think it’s more to do with the English than the language itself. England is the best, therefore English is the best, and it’s spoken by so many that one can get by in most places in the world knowing only English.

We’ve also got a national hatred, at least at some joking level, of particular other nations. The Germans, the French, the Spanish (to a lesser degree though). That covers some of the main alternative languages for us (in the western world).