... However, having been a programmer for 40 years, I certainly do see his point. Once it gets into a computer, it's just data, and data is not reality, but only an agreed-upon representation of reality.
This is similar, if not identical, to the concept that both Ken Nadvornick and I wrote about around 2013, 2014.
The critical thing is that when you have light striking a sensor, setting the state of pixels, and having an electronic representation of the image on the sensor (temporarily) and on a memory device (disk or card), that representation is ephemeral. It exists only as an electronic state that must be interpreted by other electronic equipment and a software program in order to be viewed.
By contrast, light striking an emulsion produces a permanent physical change in the emulsion. After development, the image can be viewed directly simply by looking at it. Furthermore, that image has a provenance that digital does not: the film itself was in the presence of its subject. That is, a glass plate of Abraham Lincoln was right there with him when it was created. Film of the lunar surface was right there on the Moon. With a digital image, it's fungible and a copy/paste created today is identical to the initial image - there cannot be anything special or different about the electronic state that existed when the image was first created and those of the one-millionth copy.
This is a real difference, but it does not denigrate digital photography or images. To some people, none of what I described matters - which is fine. Personally, I look at the final print (regardless of how it was created).
Digital photography definitely
is photography and is equally as valuable as film or any other type of image making. I've made photos with my digital cameras that I know I could not have made with my film cameras due to the logistics of the situation; I cherish those photos.
This whole squabble is a bit silly: like watercolor, oil, and charcoal artists arguing about which method is best (or, as in my experience, a trombone player telling me how superior his instrument was to my saxophone).