The thing I find most interesting about this and other "classic" movies such as "The Bridge On The River Kwai", "Lawrence of Arabia", "Dr. Zhivago", "Doctor Strangelove", "Fail Safe", "On The Beach", "Seven Days In May", "Judgement At Nuremburg", "Patton", "A Bridge Too Far", etc. etc. etc. etc., is what the details of these movies say about what was in the minds of their makers and in the minds of the audience for which they were intended, at the time of their making
To me, these movies constitute only one part of a "package" of what people are exposed to during their daily lives from the day they are born, through their educations and work lives, to the day they walk into a theater to see those movies for the first time. To be brief, what they see in those theaters cannot conflict too much with what they've been taught, or have come, to believe is "the truth" of the world in which they live. Many times the events protrayed in these moves bear very little resemblance to sometimes-shocking historical reality. "The Bridge On The River Kwai" is IMO a perfect example among too many.
I'm 67 and saw 2001 shortly after it was first released during the very politically turbulent time of 1968, which also just happened to be the time of Mercury, Gemini and Apollo. My "reaction" to seeing it many times since that day has evolved radically. What amazes me today is the ridiculous similarities of 2001 to currently produced, "serious" attempts at portraying, for lack of a better expression, manned space travel. (Lately, "The Martian" is one of them, but IMO suffers from some very serious believability shortcomings which I discussed at length in the following thread:
For example, the sizes of the spacecraft in space movies are probably much larger than will ever be produced. The list goes on and on, but I won't elaborate further other than saying that IMO, manned space travel may never be anything more than something interesting to speculate and make movies about. In short, the human imagination doesn't necessary dream up stuff that, given enough time, effort and money, becomes possible. Inter-planetary or interstellar space travel may turn out to be bridges too far.
As I've aged I've become much more critical of movies. But although 2001 also has some rather serious technical shortcomings, it's story still inspires in me awe of space and what is still unknown about where else life almost certainly evolved. One thing we have learned since 2001's release is that if there is "intelligent" life "out there", it's almost certainly many light years distant. That, in and of itself, constitutes a possibly insurmountable barrier to it's practical significance.
I doubt if the 4K version of film-captured 2001 is going to look much better than the 1080p version, but I'll be pleasantly surprised if it does and I'll grudgingly shell out for it for probably the fourth time.