More I get older in life, more I become both disappointed in Jiraiya and understand him at the same time. Naruto severely lacked the fundamentals, heck he did not know the meaning of chakra when he started training with Team 7. That is like the first thing taught in Academy. He did not know anything about Ninjutsu, Genjutsu or Taijutsu, his only tactic was to rush at everything, spam gajillion clones and hope Kurama gives him some chakra to finish the job. The material at hand was a total zero, a talented and hardworking one, but a zero regardless. Jiraiya probably thought that if he taught him the fundamental stuff and refined his already existing skills, he could pull him from zero to at least something. Then, through further training by himself and through Kakashi, he would figure out more advanced stuff quickly later on, which turned out to be true. What Naruto needed at that moment was not advanced training, it was learning fundamental stuff, maturing and developing parental bonds with someone.
People do underestimate the importance of maturing correctly in this series. Look at what happened to Obito, an orphan thrown into the battlefield at the middle of the war, permanently scarred and was dealt a very bad hand with parental/savior figure of Madara. Look at what happened to Kabuto, before maturing properly, he was taken away from his family, used as a spy traveling across the world without anyone or anything and thrown away like a guinea pig once they were done with him.