You're making it sound like the desire to be a Frenchman is an unreasonable requirement for becoming a Frenchman.
> abandon your own language, culture
Thank god nobody is asking this. They're being asked to learn enough French to participate in France. B1 is hard, but it ain't B2, and you'll still barely understand what's going on around you.
> requirement for becoming a Frenchman
The discussion is about permanent residence, not citizenship.
Permanent residence allows eg an employee be able to continue staying in a country without being dependent on a particular employer and having to reapply everytime they change jobs. It is gives a person who works in a country for a certain amount of time already, paying taxes etc, having the same rights as an employee.