Mistreatment is a strong word...
Sadly the game can not cater to everyones tastes. I am happy for example that the game focused more on the Ancients and the mainplot and not on Garlemald.
I understand that some players would have loved to see more of Garlemald or Garlean NPCs from sidecontent like Bozja. Yet other players would have loved to see more of other characters or areas as well and never got their wish. Think about Hingashi. We only really were able to visit Kugane and never got to see the rest of the nation. Or Dalmasca, which we only ever visit in a raid.
The game has limited resources each expansion and can only implement so much. Therefore it is not surprising that we were not able to travel through a lot of Garlean areas or provinces. Or inlcude all the NPcs and give them their finale onscreen. What we got is already more than I had hoped for, considering that this expansion wanted to wrap up all loose plotthreads.
The rolequest conclusion was in my opinion well done and gave Garlemald's story at least closure. It also showed that the effort of the WoL and scions to bring all nations together and overcome their differences finally played out. I was very happy to see them work and fight together. Nero was also a nice addition, since I have always liked him a lot. It was only disappointing that Gaius stayed away.
Something that is mentionded here and in other threads that I do not understand is, however, why some people think that this will be the last we see of Garlemald. The rolequest left all options for Garlemald's future open. There were NPCs that decided to rebuild their society and establish a new government. Only 3 young people + Nero decided to go to the moon in order to learn more about it.
Maybe we will be able to help rebuild Garlemald in a similar questline like Doma someday in the future or get a delivery questline on the moon that includes Nero and the others. I would really like to see more sidecontent like that that shows us how Garlemald's future develops.