Reading what I wrote, I guess it sounds a bit condescending. No intent to insult here, sorry if I was too harsh.
Of course I can see the appeal of the movie and I understand that of course people are free to like whatever they choose. Interstellar is still a bit special because it really has everything I usually like. I went in there with high hopes and was really happy with how much my desire to like that movie had no problems being fulfilled at all. Until that last hour. With bad movies, it's just a bad movie for me, but this one felt like I got betrayed after having already decided to love it.
But yeah, it's just a movie and I shouldn't be too invested. Great for you if you like it, I really wish I did, too.
I have seen 2001 and that one didn't bother me at all.
The whole ordeal with HAL is over, the story arc has essentially closed. They just need to reveal what they find. They get to the artifact. Then... stuff happens. Nothing is explained. I always assumed it was supposed to visualise things that are beyond our comprehension, but that's already my interpretation.
Is it a good ending? Dunno, I like it, but I can see that it's controversial. But is it something that goes against the movie until that end? Absolutely not. The movie started with 20 minutes of monkey business.