So you believe that he left her on Jakku to keep her out of harms way and still she found her way to him?
I'd wager he left her on Jakku to avoid making the same mistake with her that he did with Kylo. Together with Han and Leia, he made the decision to train Kylo in the hope that he wouldn't succumb to the dark side. This wound up being a terrible strategy, just like it was with Anakin; Force training doesn't work very well when the trainer has their own agenda for their student, and their student is already heavily morally conflicted and has their own separate ambitions. The end result is that a wedge is driven between the student and the Jedi.
Luke ultimately chose Jedi training for himself - Obi-Wan had offered him an unconditional choice, and he made the choice after facing the consequences of his inaction.
This is very unlike Anakin, who went with Qui-Gon out of hope for a better life for himself and his mother and a belief that being a Jedi would let him live out his own personal crusade. ("I think [Qui-Gon has] come to free us. Why else would you be here?"; "It's what I've always dreamed of doing!"; "I will come back and free you, Mom, I promise.") He then had a great destiny thrust upon him by his teachers, one that ultimately conflicted with his own personal agenda. He didn't choose to be a Jedi because he realized the importance of training to become one to save the galaxy;
he became a Jedi because he dreamed of using Jedi powers to make his personal fantasies come true.
We see in his conversations with Padme that this extends across his entire philosophy; he believes that the best way for peace and order to come about is for "someone wise" who can make people obey to come to power. Where Luke realized he needed to become a Jedi because he could no longer afford inaction;
Anakin wants to become a Jedi out of wish fulfillment.
Likewise for Kylo: he was conscripted into Jedi training to try to put him on the path Luke/Leia/Han wanted for him. But it turned out he didn't see eye-to-eye with his father, felt like his family was a source of weakness, and inevitably rejected their wishes for him to pursue his own ambitions. (I'd wager he shares his grandfather's idealism that someone wise and powerful can bring peace to the galaxy by force and wants to be a vehicle to make this a reality.)
Luke also has stumbling blocks in his training that are very similar to those Anakin faced: the desire to save his friends and avenge his father overrides the instructions of his masters, and almost leads him to the dark side. But when faced with the reality that Darth Vader
is his father, he realizes that justice isn't served through either offense or self-defense but through
mercy; he discovers
a kind of Middle Way. His father ultimately turns back to the light for much the same reason he took up Jedi training himself: when faced with the consequences of inaction, he was compelled to do what is right.
In the end, both of them achieve the most good by actually ignoring their training anyway; Luke wins by
rejecting the opportunity to defeat Vader, and Vader wins by
accepting the impulse to save someone he cares about. What allowed this to happen was the circumstances that led them to those definitive moments. That's something that can't be taught; that teaching in fact gets in the way of.
Rey is placed in more or less the same position as Luke. She's left on a desert planet with only hints of where she truly came from. She only leaves once faced with the immediate consequences of inaction. When she finally takes up the lightsaber, she also does so out of need, not out of an ambition for justice or a personal agenda or even because someone told her she should - remember that at first she recoiled from the Force and the saber, but only took it up when she was the only line of defense against Kylo. Once she accepts that destiny, she's able to allow herself to be guided by the Force, then she gets the information she needs to find Luke and begin her training.
She needed to be put in the position to
choose to take "the first steps" to becoming a Jedi. And the best way to do that was to remove her from all the influences that would have pressured her to become one for reasons that were less than pure, or to follow an agenda that she didn't fully accept. The movie sets the audience up for what's going on with Rey by throwing the characters around her into similar situations: Finn's moment of realization that leaving the Order was "the right thing to do"; Finn deciding that he can't run away anymore after seeing the destruction wrought by Starkiller Base; Han going out of his comfort zone and appealing to his son; etc.
Could you imagine being the person who had to put her through that, though?
Especially if she's kin?
Especially after having lived it already himself and having to make all kinds of really difficult decisions to get where he was at the end of ROTJ? It'd be absolutely heartbreaking. At the same time, it's a terrifying decision that's fraught with its own risk - Rey could very well have rejected the saber completely, or turned to hate and utterly destroyed Kylo, leading her to the dark side.
