Is finding luke a major event? It was after all presented as the driving force of events in the opening titles and drove the action for the first half of the movie.
And? The fact that R2D2 has the map (which is incidentally explained in TFA by exposition [C3P0 interpreting for R2, I believe], reminding the audience that R2 accessed the Imperial network in the previous films) is not itself a plot hole, and his timely reactivation is a convenient coincidence but not actually a hole either.
You claimed it was not a big deal because all of the major events of the film had already ended. I'm saying finding Luke is a major event, so it is a big deal.
It's Deus Ex Machina is what it is. An unforeseen event solving an impossible problem.
A solution to a problem which references no specific event or film but rather on the general idea that R2D2 once plugged into the Death Star so he downloaded all their emails.
This is also taking place in a universe where the Millenium Falcon's star charts are detailed enough to have information on meteor showers in the Alderan system. But where allegedly half the universe has lost the map of hundreds or thousands of stars easily observable by telescope.
Vader went to hoth to find luke.
Luke was on hoth when the Falcon left.
If Vader could find luke the way kylo finds rey, why didn't he capture him on the hoth Battlefield instead of searching the base?
Great question! On the other hand, how does Vader know Leia/Han are headed to Bespin?
Boba Fett.
It's the only thing of value he does.
How does Vader know Luke is on one tiny shuttle flying down to Endor?
Because he's met him before and has a connection to him.
That's the one consistency in TFA as well. People strong in the force can get an idea of where someone they've already met is, or at least where someone who is also strong in the force is when nearby. It's used three to four times. Vader when he feels Obi Wan in ANH. Vader when he sense Luke in ESB, AFTER they've met face to face. Vader/Luke in RoTJ After they've met face to face in ESB, Leia sensing roughly where longtime friend Luke is and in TFA for Kylo Ren who senses his Dad.
There's never been a time where a force user has been shown to sense and know where a stranger is.
Vader couldn't sense the location of the Falcon in the asteroids.
He couldn't sense that it was attached to the Avenger.
I would even argue that his claim they were still alive in the asteroid field was a hunch, not a force-based premonition. Or maybe at best he can sense they're alive but not when a non-force user is nearby. This would incidentally make its use in TFA inconsistent as well since Han Solo is not someone strong in the force and should arguably not be able to be sensed. But this is not fully established. It's simply the pattern that every previous instance follows.
How does Luke see a "city in the clouds" when Yoda is literally instructing him in Force Sight? How does the Emperor know Luke will come to Vader?
Because that's called premonition.
Not omniscience.
They have a vision of the future not absolute knowledge of the present.
Yoda even defines such premonitions as based on feelings.
Further, Vader's ultimate betrayal of the Emperor demonstrates that their these premonitions are at best rough ideas and not reliable.
The Force is rampantly used without apology throughout all seven films. Like I said, you can't be claiming that it's not a problem in the earlier films and it IS a problem in the latest one. From the first third of A New Hope, Star Wars audiences have been asked to accept implausible knowledge and implausible coincidences in the name of the Force. How is this new in TFA?
When is Kylo Ren shown using the force to find Rey? Did I miss a scene where he says "I sense someone strong in the force, this way!" Instead just shows up out of the blue. Twice. In fact he finds her in two strange forests that he's probably never been to before but he can't find her on his own base when he knows she's escaped.
In any case, back to my original example, on Hoth the force didn't help Vader, because he didn't know Luke at the time. So it should not help Kylo Ren find Rey on the smuggler world. It's a plothole even if you view it in light of the other movies. The only time a person tracks down another person using the force is when Vader confronts Obi Wan on the Death star.
But as for Rey, finding her could be as easy as two lines of dialogue.
"Lord Ren, troopers have sighted a woman in the outlying forest who matches the description."
"Tell them to hang back, I will confront her myself."
Bam. Done. Plot hole filled.
tbf to Abrams, I liked his first Star Trek and his second will probably be miles better than the third one, which could have been written by some Fast and the Furious script writers (they got the director, so it's almost there).
I think TFA was exactly what I expected from Abrams: a fast pacing movie without hiccups, immensely entertaining, funny and joyful, with good acting and a satisfying arc of a story. Filled with a lack of concern for details and one or two Joss Whedon-like one-liners (Han Solo's "It's bigger so what" ).
Now that the movie didn't suck and actually lived on those expectations, people ask, "why couldn't it be a better movie, I'm angry at that!", well, masterpieces are extremely rare and immensely hard to build. I feel exactly zero entitlenessness to have these movies be crazy good.
Excellence was never achieved by rewarding mediocrity.