No one is saying an upgrade path is bad. This issue owners take is the constant money pit just to maintain your market position of offering an up-to date Red camera.
Arguing that your picture is just as good as it always was is only relevant when the client doesn’t care what you're shooting with, which is fine for small one-man-band businesses (nothing wrong with that), but it's not how things work at the level of the industry where Red cameras are used.
Gene nailed it: The bad thing about Red, is once a new sensor / update comes out, the old cameras are quickly excommunicated and no longer desirable.
This kind of sentiment: "You can be "glass half empty" about it but in the end, it doesn't diminish what your current camera is capable of" is completely missing the heart of what frustrates owners.
It’s not that their camera has suddenly got a terrible image, it’s that their camera has just dropped in perceived value in the eyes of the producers and DPs that are looking to hire them, so ‘what the camera is capable’ of has absolutely diminished in terms of generating income. They can spend $10k because Jim has given them an ultimatum or accept they need to lower their rates. It’s nothing to do with image quality or ‘discounts’. It’s to do with the bottom falling out of your investment and acknowledging that is not “glass half empty”; it’s just not being mindlessly optimistic. When it comes to offering a service perceived value is everything and the fact your image quality is just as good as it was a month ago matters very little when the op standing next to you has paid for the upgrade and you haven’t.