Jumping into this with a "spicy" personal opinion.
How I would rate 2001 depends entirely on my criteria.
For cinematography and vfx I would give it an 11 out of 10. Ground breaking.
For story and entertainment, I'd give it a -1. It is an anti-film in that sense. The most mind-numbingly boring and drawn out piece of "film" that I have ever had the displeasure of trying to sit through.
And I say that as a self-professed film nerd. I admire Kubrick a lot. But I can't stand 2001, at least when I judge it by the same criteria that I judge other films.
Film is visual story telling. Emphasis on "story."
Putting aside Dave & Hal (which make their appearance so late into the "film" that I've already been asleep for 3 hours - yes I'm exaggerating), when you take away identifiable protaganoists and antagonists, with backstories, goals, motivations and obstacles what you are left with is more of an exhibition.
2001 was more of a 1960s speculative endeavour into humanity's future at the dawn of the space age than it was a story told through imagery. It lacked plot, character development, relatibility and it's pacing was so slow and drawn out that it's hard to maintain your attention throughout.
When you judge it for what it was, there is a lot of greatness there. Many of its visual effects were truly groundbreaking and influenced filmmaking for decades to come.
But when you compare it to films that you actually want to re-watch for entertainment value ... I would put it in the "awful" category. But that's just my personal opinion.
Dr. Strangelove
Full Metal Jacket
A Clockwork Orange
A bunch of not bad films:
2001
Lolita
Barry Lyndon
The Shining
Spartacus
One real turd of a film:
Eyes Wide Shut
And a bunch of forgettable filler:
All the other films he made.
Compare this to the Anti-Kubrick, Clint Eastwood, who made:
Unforgiven
Mystic River
Million Dollar Baby
Letters From Iwo Jima
Gran Torino
And a bunch of okay films:
Pretty much everything else
And it’s pretty obvious that you don’t need to be an abusive taskmaster like Kubrick to make great art.