Well my friend, you are asking one of those "Eternal" questions that probably will never be answered to your satisfaction.
I bought my first Hasselblad Camera set up some 40 years ago; Back when digital was still very much in just the idea stage. It was at that time the finest medium sized format camera for taking pictures on this planet. It was the standard by which all other cameras of this sized format were measured. It used a collection of lenses made by Carl Zeiss, and to my knowledge there were no other lenses made generically that would fit the Hasselblad body. So, you are talking about a very exclusive club when referring to Hasselblad owners.

There is also a kicker which needs to be mentioned. Hasselblad cameras and Carl Zeiss lenses were the only combination to make up imaging capturing devices for the U.S. space program. Back then, when those choices were made, they looked for simple design and proven durability, reliability, with optimum results. That was Hasselblad in spades.

Back then, my Hasselblad Camera setup was the "C" body, Zeiss lens and the film back which held the film for the camera. I had a few filters, an extension tube, a flash set up and a sturdy tripod... along with a set of studio strobe lights. That whole bundle cost nearly $5000.00 back then. It was a much simpler camera than even the simplest digital cameras available now... it was completely manual from focusing to metering to film advance.

Now, jumping ahead 4 decades, you are talking about a camera that is much more complicated, with a flawless reputation, that commands a premium price. It still belongs to only the upper echelons of serious professional photographers.

I guess the best way to finish my response to your inquiry would be to give you an analogy. It is exactly the same thing as wondering why there is so much difference in price between a high end Mercedes with all its bells and whistles, and a basic Ford Fusion. Both will perform the task of getting the driver from point A to point B. It is HOW that task is accomplished, what comfort the user derives during the trip, along with the projected image of owning the Mercedes rather than the Fusion.

Hasselblad has the reputation and the clout to command that price for their product line. They don't cut corners and they don't want to run with the pack... They want to be a clear front runner and do what it takes to remain there.

Of course this all comes with an admitted caveat; All things written above is only the expressed opinions of a single Hasselblad owner, who can no longer afford to run with the elite owners of today's Hasselblad equipment.

I hope this helps you wrap your mind around one way of looking at your eternal question. :)

Typically, the photographers buying this camera are high end fashion and product shooters. Their clients expect the best image quality possible; Hasselblad will provide that. If you are in that business and are successful, $40,000 is just another business expense and will be recouped with a few jobs. I have shot with their back designed for the 500C series and the file resulting is truly amazing.
One of their reps came to the College where I teach and brought a sampling of their cameras; one would shoot 5 exposures at different focus points and combine them to produce a 1.2 GB file: my computer had a meltdown trying to open it!