Agreed. This is dangerous territory and the huge downside to incremental upgrades. I REALLY hope there is a true PS5 though, and the PS4/PS4K are treated like the PS3/360 were. Hopefully phased out even sooner.
I'm totally ok with the PS4K if its treated as a device of THIS generation.
This is what i have been saying the whole time...Sony are trying to sell this thing as a more powerful PS4 with the same ecosystem, the same games and the same base limit of PS4...they are trying to lock the experience down to the very minute details of not even having any extra modes or features.
I don't think they would bother to do that if they were not thinking of PS4K as a mere extension of the current generation and PS4, and not its own unit that by definition just happens to need to support PS4.
They will make a PS5, and if they want to continue this pattern, a PS5K in the same manner as this gen. The only difference will be that they will have good BC throughout, to support a consistent ecosystem.
That's just my opinion of course, and i know i am going to disagree with the "iterative consoles are the future" people, but if there is BC, there's no real difference in regards to consumers having a consistent experience and devs getting a stable development base for several years.