Hello Steve,
yes, you are right. The Nazis legalized the casinos in 1933. Germany was still poor because
of WWI and the Nazis hoped to get some money from the casinos.
But the plan did not work very well. The casinos did not make much money.
The Germans still had not much money to spend, and foreigners were
not interesting in coming to Germany.
(In these times the casinos in France, Monaco and Belgium were very well visited.)
Shortly after the begin of WWII most of the casinos in Germany closed again. No one in Germany was intersting in gambling. And of course no gamblers from other countries came here.
The Nazis could not bring back the "good old times" from before 1872 when the casinos in
Bad Homburg or Baden-Baden were part of the top casinos in Europe.

Best regards,
Bjoern