Every platform this gen has had many issues with frame rates....wether it's PS, Xbox or PC. and that was before the Pro came out. It's more about optimization...which devs struggle with even on the new Pro which runs most games fine...but there is still few with issues.
Ms and Sony should force devs to realese solid optimized games.

This is making me want a Pro though to get the best experience...

Trojan horse no, yet after playing it for a couple hours, yeah you kinda want the full 30 fps since animation detail is amazing. I spend the last half hour just staring at the wind blowing through the trees, grass and Trico's coat. This is a new level of 'idle' animation not seen before. PS3 game lol.

Just 40 seconds of me standing around

https://www.youtube.com/watch?v=2J-FMiWC2vE

It is a trojan horse for a good surround sound system. It sounds great. I don't know how they do it, but Team Ico's games really make you feel like you are in the environment. Great use of surround.

Well, that is a valid worry. Some devs will possibly "move on'' to PS4Pro and make their vision on it and then scale back to PS4 and X1 and we may see very bad performance on vanilla consoles. I don't think it'll be imediate, but give it one year and it'll be quite possible.

Exactly. I'm not expecting it to happen overnight, but there will be pressure to focus on Pro versions more as Pro numbers keep growing, and if Pro ever becomes the main SKU, it could start looking pretty bad for the regular PS4. Perhaps nothing of this is ever going to happen, but it still worries me, and I don't like it in console gaming.

I'm buying a PS4Pro, I want better showing on it, but since I'll keep PS4 to the other house so I don't have to carry it up and down I don't want the PS4 vanilla version to be garbage.

It doesnt work that way.

Every generation had these "issues". Nowadays, there is much more focus, because... sensationalism. It generates clicks, its easy to point at the supposedly guilty culprit, rile up the crowd, the dear customer audience. Easier and more profitable than to address real and more complex issues, than to be truly educational.

Other than that PS4 OG is the vast majority of sales base which they make or lose their profit on...
How long does high performance AAA game dev take?  
So if they are starting their purported Pro-centric game RIGHT NOW, it will be out in 2 years optimistically.
Well, 2 years from now would be when new PS5 gen would be kicking in had Sony not done half-gen update.

People want to take the normal-existing-status-quo performance problems and attribute it to Pro.
When if we are real, we know devs would let that performance issues happen without any Pro model.
Sony is clearly using Slim to push MASS sales volume, which will CONTINUE to attract dev attention.

If people worry about PS4 performance, they should demand variable resolution games.  For reals.

Ever think that the time Sony will phase out PS4 og-spec Slim completely will be when PS5 drops?
Or that had they not done a mid-gen Pro, they would have accelerated the introduction of PS5?
So when PS5 drops, I expect initial cross-gen games to possibly exclude og-spec PS4.
But in the absense of Pro, those games wouldn't ever have come to PS4 og-spec,
because PS5 would have intro'd earlier and cross-gen development would have ceased earlier.
The Pro in fact extends the viable length of PS4 platform for og-spec as well,
AND facilitates a later entry / higher spec for the subsequent PS5.

I think my last sentence pretty much covers what you just said. And a friendly tip regarding readability: don't try to line your text manually. It ends up being harder to read in almost all cases.