The Nikon D600, D800 and D4 are the same camera inside

On the other hand (from the linked article):

'Back when Nikon ruled the pro 35mm world, all their 35mm cameras took the same pictures. The only differences were how tough and how fast they were. Consumer cameras like the EM were plasticy and worked OK, while the F3 was tough and fast, with the FE in the middle. All took the same film and same lenses, had the same meters, the same automatic modes, all focused the same, and all took exactly the same pictures.

You paid more for speed and durability, and Nikon advertised to everyone implying that if you wanted to be cool or to be a great photographer, you needed the most expensive camera — even if you were shooting portraits or landscapes, none of which require speed. Nikon showed Galen and other sports and action pros, somehow implying that even if you didn't need speed or durability, that you still needed to buy the top pro camera if you could afford it. Nikon never let on that the EM took the same pictures, cost less, and did the same thing with a lot less weight.

Unless you were actually shooting sports with a motor drive, it just didn't matter. '

This reminded me of some other brands which practice the "anti-feature" on their products. There's an IP Camera brand which uses the same PCB board on their range of indoor cameras but blocks usage of some components on it such as MicroSD reader. I noticed that when I opened one of them, it had MicroSD reader inside but it was blocked by the case outside. That's done to justify its lower price, what a foolish thing to do really.

There were also talks in the past about Microsoft turning off features off the Windows to justify the price. Again what a foolish thing to do.

I see an article which says "they're the same camera, they're the same insides" over and over again - and absolutely no evidence to support the claim. Am I missing something?

is a bit like games selling DLCs?