Cite me your evidence for that. German bureaucracy, and European governments generally, were very controlling, LONG BEFORE the Nazis.
It's very easy to blame anything we don't like in Germany on the Nazis...and tends to end the discussion, eh?
Truancy laws....found in the USA from the 19th Century onwards, and in Europe before the USA, corresponding with mandatory public education, are what generally have been used as "anti-homeschooling" regulations.
I'm not saying German law about homeschooling is good--but understandably GIVEN THEIR HISTORY they want to make sure little radical groups are not mis-educating their children.
The biggest German fear now, is that the Moslem immigrants will homeschool their kids to be Islamic terrorists...
Homeschooling is illegal in Germany since Hitler banned it in 1938.
http://www.brusselsjournal.com/node/1330
One article on parents who tried to do so. You’ll find extensive articles on the subject. Germany is particularly notorious on this draconian ban.