Like Batman movies everyone loves them at first, but get upset at the sequels.
It was the opposite for me. While I liked it from the beginning, I enjoyed it even more with each sequel, with Arkham Knight being my favorite.
I never understood the complaints about the Batmobile in Arkham Knight, it's really exagerated because you don't have to drive it that much if you don't care about it, people made a huge deal out of nothing, and I also think the Batmobile gameplay was actually really cool, loved the Arcade feeling about it.
The rest of the game is also absolutely amazing, so hating on a whole game just because of maybe one hour of driving in a 40 hours game seems ridiculous to me.
The main complaint I have about Arkham Knight is how the ending is hidden behind a completion %, so if you just beat the initial main story, you won't get any ending at all, which feels very anti climatic and... a dumb decision.
At least if you have the DLCs, beating the DLCs villains unlocks enough % completion to trigger the main ending, so it's... decent, but it should have been done differently.
Talking about DLCs, I think having the GOTY edition of Arkham Knight is crucial to really enjoy it, because the DLC content really did add ton of value for me, I really enjoyed playing all the different characters episodes, playing all the combat challenges etc, it was among the most fun I had with the game as a whole, but I really like arcade scoring etc, so others might feel differently.
Since beating Arkham Knight and the DLCs, I always wanted a game about the rest of the Bat Family and not just batman, these DLCs really made me want something like that, so when Gotham Knights got announced... I was super happy and I'm really excited for it, it's my most anticipated game.
Arkham is a great series as a whole, but unlike a lot of people (from what I can read around), I really prefer the open variation of it, not a fan of a "dungeon-only" style of Arkham Asylum, even if the game was still really good of course. I like my free roaming as a "super" hero.