Everyone has a reason; everyone spends for value received. I am not going to argue against people who need/want an e-book "hot off the press" and will pay whatever the asking price may be.
I'm not so impatient. My next breath --YEP! That I want NOW!! A book or a movie or anything less crucial to survival: I can afford to exercise my purchasing power strategically.
The market dynamics: as has been ably pointed out in previous posts, publishers will charge whatever they can, and will deliver whatever level of slip-shod production they can get away with.
I used to work in the printing industry. Yes, technology has changed since then. But in producing a physical, printed product there are --and will always be-- physical constraints that mean fixed production costs, to some extent. There is simply no comparison between the huge costs in making printing plates, buying paper and ink, running the presses. . . then binding the books, shipping them out of the plant, warehousing them, and then shipping them out again (either to retail outlets or to internet customers) -- versus digital reproduction!
In economic terms, sellers and buyers have a conflict of interest, as well as a common interest. The common interest is distributing a product to folks who want it. The conflict is the price. I'm not doing myself any favour by encouraging sellers to believe they can continue to price-gouge me on ebooks, so that they can make a higher profit margin than they do on their standard (printed) product.