the movie was considered slow back when it was released.
it was also highly disliked by both critics and the audience.
like most kubrick films, it was far ahead of it's time. so time is what it took for people to appreciate this masterpiece, which is widely considered to be one the best films ever made, often put on the top spot in rankings.
but yes, it is slow, it is not an entertaining movie, it is not meant to entertain.
and I am very glad people talk about it a lot lately, because of interstellar of course.
I just cant help not comparing the two docking sequences in the films, where the ships need to rotate to dock on the station.
sure, in interstellar it's a dramatic, hectic situation and in 2001 it' s a textbook docking witthout problems.
but still, comparing these 2 scenes really shows the difference between a movie that respects it's audience and a movie that thinks only stupid people sit in the audience.