It’s a geopolitically grounded form of Protectionism.
I don’t like that smaller countries have to rely on larger countries that don’t have their best interests in mind. Not only should France buid its own tech infrastructure but so should every other country that can build it.
In the post-NSA age this is vital if you want your country and its population to be secure against cyberattacks and mass surveillance by great powers.
this isn't just 'jerbs' rhetoric. Having French data on French soil guarantees that if push comes to shove French authorities are in control of their citizens' data. It's a matter of national sovereignty. If companies have billions of dollars worth of physical infrastructure located in the countries they operate you can be sure compliance with local laws will actually happen.