Yup. The Jedi, while good, were way to much of a religious group set in their ways. They thought bringing balance meant the end of the Sith and darkside as a whole. Jokes on them.
I also like looking at the angle that Obi-Wan and Yoda were trying to make Luke into an assassin to take out Vader in Ep 4 and 5. Even when Luke went to face Vader in Cloud City they weren't too upset at the prospect of him losing because 'there was another'. They truly didn't understand it yet then either.