Not really, he clearly implies rubber banding as a concept is pretty terrible. It takes reading that comment with blinders on to not see that. Second, the Sprawl is arbitrary, because it does not solve anything. "Tall" is no closer to being competitive than it was before, Tech Rushing is no less viable than it was before. The goals they clearly wanted to achieve, were not. Therefor, it's clearly just punishing Wide for being Wide.
Sprawl is not a complete rubber band mechanic, mainly because it doesn't allow smaller empires any rebound mechanics. If you're shafted by an early war, poor starting position or something else there's very little you can do to recover. You can't tap into a special comeback mechanic, you can't count on some other feature (like stability and unrest in EU4, for example) to screw with a larger empire, you are stuck being dead last unless another empire intervenes. Sprawl isn't so much a rubber band mechanic as it is a resistance mechanic that's meant to make it harder for a snowballing empire to reach critical mass. By making tech and traditions cost more you off-set the absolutely massive science advantage accumulation that a big empire can have over a smaller. As others have said, this off-set will not be higher then the extra research you get (assuming that you still invest in science obviously), it will only make the adjusted science gain from each researcher or system lower then for someone with lower sprawl.
Since this is the goal they talked about achieving, curbing the runaway science production ramp in the mid-game, I'd say sprawl does exactly what they intended.
so what now... are the devs fault or not... and IF they are fault what you admit they can be... how shall someone call it? You even mentioned in a former post that "dirty" coding can lead to problems... but who does the coding? The devs... and IF they code "dirty" too much, things will break more easily with every update / DLC that means that the "dirty" coding leads to a justified "they cant control their own game"... or is my logic flawed? I dont think so... i rather think you work in a similar job and you hate to deliver "BAD RESULTS" but is often forced to do so... well knowing you could do better...
I work in a job far removed from software programming and my employer is in the public sector, so that's not even close. What my work does contain, and which I have great empathy for, is great constraints on how much time and resources I have to do my job.
The devs are ultimately responsible for what they deliver to their customers. Here we need to make distinction between Espionage-bad, obviously undercooked, broken or buggy content, and Sprawl-bad, design decisions I disagree with. Sprawl-bad is subjective and we can easily stop talking about that but that the devs deliver some things that are Espionage-bad is to be expected. Just as it is to be expected that a physician occasionally misdiagnoses an illness, a cook screws up a meal or a scientist draws the wrong conclusions from their data. Because making software is really hard and adding things to established software is even harder, especially if code that was fine five years ago turns out to not be suited to what you want it to do now.
The Stellaris devs aren't told to take their time and use whatever resources they need to make the next DLC the bestest DLC ever delivered. No, they are given a budget and a release window and are told that the DLC needs to be out by then (and most likely already have the budget and release window for the next DLC after that lined-up) and then are set to work. And at that point a thousand things can make their budget and deadline much harder to hit. Maybe the design turned out to be boring to play. Maybe the initial code was too much spaghetti or did weird stuff with some other part of the game. Maybe the artists couldn't deliver good enough assets or their assets clashed too much with something already in-game. Maybe the forum went up in arms when they heard about the content and demanded something new.
These things happen and affect the final product. That doesn't say anything about the devs being bad, it only tells us that they aren't magical über-mensch that never make mistakes or bad calls. So yes, the devs are responsible for the product they put out. But that they occasionally put out a sub-par product does not mean they are bad at their job. If Stellaris had gone five years being an unplayable mess and all DLC only contained buggy, broken mechanics that everyone hated, then there'd be a case for calling them bad. But since that's patently not true, maybe we should give them the benefit of doubt instead? Because most of what they put out turns out to be good and playable and enjoyable.