When we talk about the islamcritic stance that the liberal have had, and is why ms. Frederiksen just had received a lot of praise. Let me try and define and describe it.
A citizen HAS to share the virtues and values of a given polis (according to Aristotle). It takes many generations for at new citizen to begin sharing the values of a given polis.
Therefor a citizenship should be given, when the prospect citizen has become a part of the polis in terms of culture and political adherence.
This is constrasted with the French Republic traditions that holds human rights as the main view; enlightenment, rule of law and democracy.
My conclusion has been, that a new citizen HAS to respect the rule of law, democracy and human rights.
If not, this potential citizen can be dangerous to the public.
So at one hand, there is a path to citizenship, if the said new prospect, works on his adherence.
It can take many generations before this is the reality. As we see with Islamists, who have a different idea on law, democracy and human rights.
So, because of this, a polis can reject a potential citizen if they do not adhere to the basic rules defined in the French Revolution.
G-d bless the power of Democracy. May they prevail.