Not only French companies, but also banks, hedge funds, companies like Google and so on...
I was saying that in an other comment, but recently Google Paris organized a programming contest. All teams in the top ten came from top schools (mainly ENS, but also ECP and X) whereas 42 performed extremely poorly.
There's a reason why employers are biased towards elite schools.
Does this provide real proof that the model on which 42 is based is wrong? Moreover, how well does a score in this programming contest correlates to real world performance?
From experience, the strengths of school networks is a much stronger reason why employers are biased towards elite schools. Please note that I'm not saying elite schools aren't good (it's a pool I hired and will hire from), I'm just welcoming the initiative and wondering how it will pan out.