You don't get out much. This kind of argument that Umbran is talking about comes up frequently. She's a Mary Sue, not Luke or Anakin (for whatever deranged reasons). The double-standard comes up a lot, even on these boards.
Ok, I'll try to explain the complaint against Rey and why it is not a double standard, but based on a comparative and real flaw in the writing. Keep in mind that I'm not sure the problem with Rey would make my top 10 list, but it is a real flaw. The problem with Umbran's argument is that it deliberately simplifies the argument down to something that does sound ridiculous, but then you can do that with any argument.
So, as I said, I thought the initial introduction of Rey was pretty good. In her establishing scenes we learn that she is a self-reliant scrounger living on a desert planet, and that she's learned how to survive. This is pretty good background, but it does - I think deliberately - invite comparison to Luke. Both are 'orphans' (or so we think) on desert planet dreaming dreams of far far away. Rey's costuming even calls out Luke's costuming to some degree. So, here is our new Luke. Luke, as I argued earlier, is a character that is about to embark on a Bildingsroman. He's about to be involved in this archetypal coming of age story which involve him discovering and learning to use his powers after many trials and hardships.
What story is Rey about to be involved in? It doesn't have to be the same one as Luke's of course, but what challenge is Rey intended to face? Let's look at Rey and Luke point by point.
Luke early on is beaten unconscious in an encounter with sand people, and has to be rescued by Obi Wan Kenobi - a veteran wizard-knight who will mentor Luke for a while. Rey on the other hand early after we are introduced to her, beats several thugs up using her staff - the first of several demonstrations that learning to fight will not be one of the challenges Rey is faced with.
We learn Luke is a bush pilot, but in an early scene he is speaking with a real experienced pilot about actual travel between the stars, and Han Solo puts Luke in his place real quick by saying, "Traveling through hyperspace isn't like dusting crops kid..." In Rey's case however, when she encounters the same veteran space pilot, she actually puts him in his place aboard his own ship, by demonstrating greater competency and understanding than he has. So clearly that isn't one of the challenge she has to face either.
Nor for that matter is learning Wookie a problem. She immediately is conversant with Chewbacca as well. Exactly why, we don't know, but she definitely won't be needing a translator droid or an astromech droid. She has those skills covered as well. Compare with Luke's struggles with alien cultures when he's thrust into the unfamiliar territory of the Mos Eisley cantina, and again needs rescuing by more experienced characters.
A bit later on, Rey - having just learned that the force exists - uses a Jedi Mind trick, demonstrating remarkable control of the force without the need to practice or to struggle. So clearly that isn't going to be a challenge she has to overcome either. Right from the first time she encounters the Black Knight nemesis of Kylo Ren - the Darth Vader to her Luke - she is a match for him in every respect. Although Kylo Ren demonstrates a degree of control of the dark side of the force that is the equal of his idol Vader, Rey is able from the first encounter to defeat him. Compare with Luke, who is saved from Vader in the first movie only by the timely arrival of others (Han and the spirit of Obi Wan), and is defeated by Vader almost completely to the point of trying to escape by suicide in the second movie.
Likewise, in the second movie, when Luke goes to train with Master Yoda, we are treated to a montage of scenes of failure - his arrogant angry dismissal of Yoda because he doesn't match his biases, his failure to control his fear and emotion in the cave, his failure with the X-Wing. Throughout the training, Yoda is continually disappointed in him, and repeatedly reminds Luke of his weakness. No one ever reminds Rey of her weakness (except arguably the villains, who in doing so are being villainous). For one thing, Rey doesn't really seem to have one. Immediately upon beginning to train Rey, Luke is awed by her. Luke is impressed. She has phenomenal power. He doesn't really have anything to teach her, and he not she is for the purposes of the story the one who is in the wrong and needs to learn something. So clearly acquiring power and wisdom are not challenges Rey is going to have to face.
Oh yes, and she's a skilled pilot as well.
In RPGs, you have an ensemble cast, and in an ensemble cast there are two things about a character you want to avoid. You can't have a PC that is good at nothing and contributes nothing. If you do, you have a Jar Jar Binks. Nor can you have a PC that is good at everything and who needs nothing, because then there isn't any way to share the story. Indeed, there isn't really any story, because that PC doesn't really have any challenges to overcome by themselves or with the help of friends. On this spectrum, Rey is much closer to the PC that doesn't need anything. No one is allowed to put Rey in her place. No one is allowed to remind Rey of her weaknesses. Rey for the most part doesn't need rescuing. She is in fact self-reliant.
But this raises the question, "What story are you planning to tell with this character? What did you have in mind when you conceived her?" Or to put it another way, "What is the central conflict that the story is going to resolve?"
It's not just that Rey is a pilot and Luke is a pilot. It's not just any one of this points which by themselves aren't all that important. It's all these points taken together that demonstrate the problem.
You see with Luke, because of all of his weaknesses and failures, when he gets to the moment where he can say, "I am a Jedi like my Father before me", it is a moment of tremendous power because he has arrived at the end of the road that he unknowingly glimpsed when he was staring off at the Tatooine horizon. We the audience didn't clearly see where that road was going, anymore than Luke did, but we struggled along with him.
Rey isn't even on a path. And since she hasn't struggled, when this story finishes, it won't have been a journey and not mysteriously it's going to feel pretty hollow however they decide to finish it, because Rey really hasn't had any movement with her character and it isn't clear what interesting things you could do with it. I could I suppose be wrong and there be some deep and meaningful conflict that has been well foreshadowed, and suddenly all the Chekov Guns are going to come off the wall and there will be a deep and dramatic tying up of threads, but I'm IMNSHO a pretty good writer, and I don't think that's going to happen.
That's the argument against Rey as a character.
