Is anyone saying "your PS4 will run the game the same way as before" at least reading the OP?
Its clear on the OP that some devs will target the 4K and the OG will suffer "sacrifices".
Sacrifices over the ps4k version. That's obvious, just like the Witcher 3 on ps4 suffer from huge sacrifices versus the same game running on a beefier pc.
That doesn't mean the game is running like shit and is unplayable.
Your ps4 is still a ps4 with the same spec as when you bought it.
It will not run game better or worse than now.
The ps4k is the same platform with same architecture so the differences are even less than for the Witcher 3 on ps4 vs beefier pc.
Developers would have to massively fuck up if a game isn't running well on ps4. It would mean that they are trying to run a game that shouldn't exist on the console. Just like hyrule warrior on 3ds.the issue is not that the n3ds exist, but that someone approved the 3ds port. They shouldn't have been an hyrule warrior on the OG 3ds. And because Sony is bent over the fact that every game should be playable on both the ps4 and ps4k, because the whole point is to expand the userbase, this issue shouldn't exist on the ps4.
Another thing to keep in mind is that the ps4 is the hot item right now, while the 3ds is old and don't sell anymore. Another point is that hyrule warrior is already a port of a game running on a much more powerful console with a completely different architecture. There will never be a case like that with the ps4, not until the ps4 is way out and someone decide to port a game from it, a very unlikely scenario.
I don't see anybody blaming the pc version of just cause 3 for the poor performances on console. They just had to make sacrifices in order to run the game on consoles, but there are no evidence that the game would have run better if it was a console exclusive.
The concept that games will suddenly run like garbage because of the existence of a ps4k version defies logic. If the games run like garbage, it's because of the low spec of the ps4, and that's why we need a ps4k. It brings the choice to play games on console with better performance, just like on a beefier pc.
If you don't mind the lesser performance, you can still enjoy your ps4 for the rest of the generation, and if you are willing to pay more for novelty and better performance, you can upgrade and give your old console to a friend or family member. The ps4 global userbase is still growing and there would be even more incentives for publishers to make game for your preferred platform.
Your argument would be valid if the ps4k wouldn't be the same architecture as the ps4, or if Sony didn't care about the ps4 anymore.