>>3187563>The designer of that camera? Because he didn't want to be compatible with the #2 camera company in the world?Every camera system with interchangeable lenses has what's known as a flange-focal distance. That's the distance from the flange (the mount where the lens attaches) to the focal plane (either a piece of film or a digital sensor).
This is a 35mm SLR system. Because it's an SLR system, it will have to have a mirror box with a reflex mirror in it. Because it's a 35mm system, it will have to have a 35mm-sized mirror.
This puts a lower limit on the flange-focal distance for lenses that can be mounted on this camera--it will only be able to use lenses designed to focus a 35mm-sized-mirror distance away or farther.
The Sony E-mount is a system designed for a mirrorless camera. As such, they designed the mount with a much smaller flange-focal distance than any SLR, because they didn't need to accommodate the size of a mirror box in the middle. On the plus side, this means that a Sony E-mount camera can adapt pretty much any SLR lens onto its mount fairly easily. On the minus side, this means that it's nearly impossible to adapt an E-mount lens onto anything else.
The only way they could add an E-mount would therefore to be to add some fairly serious optics in the middle. This could theoretically be okay, if the optics were designed for one specific lens, but a general-purpose solution is going to give terrible image quality.
And if that weren't enough, it's designed to be a relatively mechanical camera and the E-mount is all electronic. There's no way to control the aperture on the Reflex camera, for instance, nor a way to power the lens to control focus (since many, if not all, e-mount lenses are focus-by-wire. I.e., there's not a mechanical connection between the focus ring and the lens elements; the focus ring tells the camera where to focus the lens. Even when manually focusing, the camera's electronics are still involved).
