Not all die. So there is still a very significant number who try to come to Europe but there are no exact figures, neither this way nor with regards to their forced return except the number of those actually deported (because these numbers are LePen voters' delight...).
Fact is this debate lacks facts - no matter who it is who is not going after these figures or who is deliberately withholding them.
What also strikes me is that you say that people (everyone?) has the right to stay in France (no citizenship needed? no Green card? no visa?) - and then, you talk of thousands of illegals in France.
So, again, it seems that you and I lack facts.
An unfair law that serves no purposes should be repealed even for one death.
Legally, some categories of immigrants have the right to remain in France and thus to get papers (Carte de séjour) without asking for the French citizenship. Ill people who could be healed if sent back to their country, family of people who have the right to stay in France (because the right to live with one's family is a human right) ; usually, foreign employees have no limit to their visas... But even for those being illegally in France, forcefully deporting them requires more arguments than simply wanting to appease racists. Un roi sans divertissement est un homme plein de misères
I DON'T KNOW whether it is necessary.
"Family of people who have the right to stay in France (because the right to live with ones family is a human right)" - Sure.
What I mean is that the deleterious effects of the policy are established, even if some of the problems are not fully quantified. So the debate should be about the need to control or limit immigration ; and even if such a need were "proven" (which will have to depend on a whole lot of assumption about what is "good" for a country), whether the policies being applied are not overly harsh. Un roi sans divertissement est un homme plein de misères