Have you ever played with the firmware on an A7S2 or one of the old jailbreakable models? That's why: while it may be based on Linux with some weird Android layer on which PM apps are based, it is an utter UTTER mess.
Sony is a camera company, not a software company, and it shows in whatever they touch.
Samsung NX was going towards the 'smartphone pro camera' that we should be at by now, but they pulled out because they probably saw the future of it.
Strangely, some are starting to do software better -- so they can monetize data they collect.
Photography is weird in that the people still buying cameras pretty much just want the same old Canon/Nikon controls and menus that they are used to, and have a workflow already in place. It is really difficult to get these people out of that mindset even though it would be amazing if you were able to take a photo, it would get automatically uploaded to the cloud, where you can access and edit/publish it through any device. Even though this would benefit a lot of professionals, many wouldn't want to change their workflow to allow this.
Why is this not a firmware addition? Why is this windows only? Why the ILCE-5100, but not the ILCE-6000 which is _super_ popular? Why is the PlayMemories App stuff still a unusable mess?
Sorry, was maybe a nice idea in the beginning, but the execution is disappointing. I'll stick to my capture cards and stay on the lookout for a proper camera. The zcam e2-m4 is looking better every day I have to work with this stuff...