Social mobility is very low in France as well and education is pretty much free.
http://www.theguardian.com/news/datablog/2012/may/22/social-...
Social mobility is the movement of individuals, families,
households, or other categories of people within or
between social strata in a society. It is a change in
social status relative to others' social location within a
given society.
http://en.wikipedia.org/wiki/Social_mobilityCombined with funding based only on the number of students provided by the govt. the quality in education possibly doesn't differ enough to provide any effect on social mobility.
Not saying they are worse than the german system, but certainly not better.