I've never understood this criticism. I mean, Luke became an elite Jedi after what, a few months with Yoda at most?
Luke and Han left Hoth at the same time, and even if you do some tinkering with time dilation and sublight travel to Bespin to stretch out the two parallel storylines, Luke doesn't age while he's on Dagobah, so he can't have been there THAT long. And after a few months of training (that he didn't exactly excel at) he's not only competent enough to barely escape an encounter with an immensely powerful Sith Lord, he's also mentally strong enough to resist the temptation to join him in a moment of despair. Anakin himself failed that test.
Then instead of going back to train more, he spends a few years on his own, and by the end of that time, he's a powerful enough Jedi to take down two of the most powerful Sith of all time *at once*. Qui-gon, a Jedi Master at the peak of the Old Republic, double teamed one Sith and didn't live to tell the tale. So Luke's tale doesn't exactly involve decades of dedication and training either.
I'm not saying that the OT is a bad story because of that, but I would definitely say that Rey and Luke have a lot in common as characters. The SW universe had clearly set a precedent for "plucky hero rises from obscurity to defeat bad guys" storylines. There's a lot to criticize about those movies, but I don't think the concept of Rey as a character is one of them.