This film is made specifically for hardcore Star Wars fans.
I finally saw Rogue One the other day. I actually think the opposite: The Force Awakens is a more attractive movie to Star Wars fans than people unfamiliar with Star Wars, but I think Rogue One is a better movie for people unfamiliar with Star Wars even with all the easter eggs. Without the easter eggs, I think the movie stands alone as sort of a "Dirty Dozen" set in the Star Wars universe that you don't need to know a lot to appreciate (although it helps).
The one thing that I think is unequivocally a gift to the fans is the ending. We all know Darth Vader is the boogeyman of the Star Wars universe, but we never really fully see that in an actual Star Wars movie. That scene at the end is a culmination of all that the prequels showed about the power of the Jedi and all the menace implied by the original trilogy.
Probably the thing I think the movie did surprisingly well is how it portrayed the rebellion as being this fragile thing teetering on the edge of collapse, and how it was the people who were doing the dirty work of fighting it that understood that the best. Yes, having the rebel fighters rally around Jyn was a little cheesy, but for me what sells it is later when the rebel HQ gets word that an assault has broken out on Scarif and Mon Motha asks for Admiral Raddus, only to be told that he's already heading to his ship. Its pretty clear that Jyn isn't some magical rallying force, it is that much of the rebel fighters were looking for an excuse to fight, understood they were possibly making a last stand, but just needed a little push to set them off.
And a word on the Death Star, specifically the reactor vulnerability that people have been calling idiotic for decades, and was addressed in part in Rogue One. Personally, I've never had a problem with the Death Star vulnerability. That vulnerability is not difficult to explain as something other than sheer stupidity. It requires firing weapons down the one exhaust port that matters in a machine that is supposedly about 150 kilometers across. That's comparable to finding a target the size of a beach blanket placed randomly somewhere in South Carolina. It is possible there are thousands of similar exhaust ports. It is possible (almost certainly) the exhaust ports are necessary and cannot be eliminated. They are shielded against just shooting down them (which is why you have to use physical weapons and you cannot just shoot at them from above). Even when you do shoot down them it almost never does anything. I always assumed the vulnerability was something subtle, that the perfect shot down that exhaust port, and only that exhaust port, destroys some critical set of power-related components which causes the main reactor - which has to be a massive and potentially easy to overload generator given what it powers - to basically self-destruct. This happens a lot in engineering all the time, where things are designed that are so powerful they are powerful enough to destroy themselves if they do not work in a very specific way. The main engines of the space shuttle, for example, will destroy themselves due to overpressure if they do not ignite within about one second of fuel flow start.
Now that Rogue One establishes that that vulnerability is not an accident but a deliberate act, it does seem like it could be an act of genius to me. I can imagine designing a system such that it contained a flaw that cannot be trivially removed because it is inherent in the design. Any attempt to eliminate the flaw creates problems elsewhere. There are historical analogous examples. As an engineer myself, I'm perfectly okay with this narrative. It is what I might have done.