My point is, a pro choices might be irrelevant to us. He's driven by the need to make money, and less to enjoy photography.
In this case, one of the reason for going Sony was that Sony equipment was "more disposable" than Nikon's, easier to write off in the event of a theft/robbery/meeting angry people. Do we expect the same conditions?
Keep in mind that some people are enthusiastic about a brand because they got certain advantages.
Indeed, that video is a good PR stunt for Sony. I'm a Pentaxian, though, I don't care about marketing
The D810 is an amazing camera at a good price though, I'm not sure what do you mean by "old technology for insane prices".
Neither of those extremes are any good, probably, and a very bad analogy to our discussion. By such standards, the "smart" choice would be a Dacia Logan (with a tiny, "eco" 0.9l engine).
The A7 is a retired model; perhaps it didn't sell as well as Sony hoped and there are a bunch of them sitting in warehouses?