Boiled down, you're saying Paradox shouldn't remove exploits from EU4 because it can make you do better, often unreasonably better?
Yeah, no.
The problem comes when you make fabricated pretend definitions of "exploit". Paradox flat-out said they don't have any objective, pre-defined criteria to differentiate between "exploit" and "random action X that random person Y happens to not like". They just define each action as exploit or not on a whim.
That leads to unjustifiable/nonsensical decisions like "nerf away primitive ships" while simultaneously telling people "realism arguments are useless, argue from gameplay". When pressed for the gameplay reason that "primitives" can't build ships or utilize colonial range, an over-nerfing to the point where they couldn't access areas they even did historically? Nothing. Pdox had nothing, still has nothing.
Apparently, building ships was an exploit, but only if you were sufficiently disadvantaged in the first place. Found a way to not have to wait 80 years on this start? BADWRONGFUN. YOU MUST WAIT DOING NOTHING. I WILL EVEN SAY DOING NOTHING IS FUN. That's the answer we got.
Same thing for foreign core recruitment, truce time manipulation, stability hits wrt peace deals, strait blocking changes, and many more. None of these have any even implementation based on history. Similarly, none of these have even implementation based on gameplay. Without operating consistently on their own criteria, Pdox has often shown implementations indicative of a systemic flaw in their approach to the game. Any given reason to do anything only matters sometimes, and mechanics are removed or altered on unsound/arbitrary reasoning. Consistently.
OP's reference to "badwrongfun" is absolutely relevant to this practice and he does not deserve the amount of disagrees he's getting here, but that he received so many is indicative of the direction things are going.
I think rocket jumping falls under the category of emergent gameplay. It's not really the same as cutting loopholes and exploits in a strategy game.
"I think building units in foreign cores falls under the category of emergent gameplay. It's not really the same as cutting loopholes and exploits in a first person shooter"
There is a reason I could make the above quote, and that reason is not good for your exploit "argument"

.