The fact that no critic or viewer can really pin point what this film is actually about speaks volumes for the genius of the man. It is more of an experience that a narative certainly. There is enough visual sumptuousness and tension in the performaces to last many a viewing. Kubrick certainly gives you your moneys worth.
Like Full Metal Jacket before it (as well as 2001), there is no real point to the narative. It is not that it is nebulous in terms of it's linear structure or plot detail, its more that you just never really know how you are supposed to react. This in itself is deeply unsettling. Tom Cruise in the dress hire shop in total confusion as to the mad events that are going on around him is typical of how the viewer can feel. Do I laugh, cry, agree, disagree ?
Full Metal Jacket was able to convey the horrors of war, the brutality of the individual and many other contradictions, without ever pretending that there was anything but the flimsiest plot. Eyes Wide Shut touches enough nerves about all manner issues without ever bothering to pretend that they form a part of the whole. Drugs, Sexual perversion, HIV, transvestism, infidelity, violence, death and all manner of other things come and without ever leaving the viewer thinking that they are being assualted by the issues, or being asked to take a stance.
I can understand why some may find it infuriating, pointless, or just plain dull, simply because it is just so different to just about anything else you would ever see in mainstream cinema.
Okay, it's not his best work, but it acheives levels of greatness that most other directors can only dream of. He may not ever have acheived the hights of Clockwork Orange and 2001 again, but there again who else has in the last 30 years either?