After Order 66 and the Jedi Purge, most of the Jedi were dead. Even though Luke was a hero in EP VI, he didn't have much knowledge of how to teach and build the order. You don't get to reconstruct it so easily after it being totally annihilated. So we saw Luke had failed.

In the old EU, we saw it got built so easily after a couple of years, so many "Jedi Purge Survivor" pop out, making the tragedy a joke. Even Mara Jade, the Emperor's Hand got to become a Jedi Master. That's ridiculous.

Yes i agree, i too didn't think it made sense that the order was brought back so fast, they even had the temple on coruscant back to glory and operating the same as they did in the past. It never made sense to me that Luke built the Order from scratch almost overnight after maybe only having a few months training under real Jedi Masters.

and him and his nephew Jacen pulling powers out of their backside like it was nothing