A player should be able to safely assume that any mechanic or feature provided by the developer in the game itself was intended for use and will not be detrimental to the experience. Developers, for their part, generally design based on the mechanics they have provided to the player. If they don't design around those mechanics, it's bad design.
I have to disagree on principle, because that whole paragraph sounds dangerously close to PoE design philosophy. "Players are making shitty builds and having bad experience because of it, therefore we have to dumb down stats to the point where they barely matter and any build is viable and not detrimental to the experience". This is an approach that I can't agree with. Good games provide you tools to shape your own experience, and allow you to face the consequences of misusing those tools and making bad choices.
This is a principle applied to game design, but can apply just as well to accompanying save system. I just don't see the point of spending devtime to prevent people from doing something obviously stupid. If they fuck up and have a bad time because of it, who cares? They stop playing the game? Good riddance.
Developers adjust for savescumming because they expect you to savescum. They expect you to savescum because they gave you the tool that enables savescumming within the game itself. If they do not design around savescumming but give you quicksave anyway, then they further incentivize savescumming because it will be even more effective for achieving the player's desired outcomes.
When those systems were created, they didn't expect you to savescum. That's why I mentioned the OHKO spells earlier. They were included because they are a fun mechanic, and the possibility of morons to ruin their fun by savescumming 1000 times to bypass every boss encounter, didn't occur to the devs back then, because why the fuck would anyone do this?
Modern gamedevs, know from experience that people indeed are dumb enough to do this, but instead of ignoring it and letting dumb people be dumb and filter themselves, they decided they need to save them by adjusting the game, and in the process making it worse for people who do not savescum.
For those of us who agree that savescumming is detrimental to both gameplay and game design, there should be no qualms about replacing it with a limited save system. It has already been demonstrated repeatedly that limited saving does not mean unnecessarily lost progress. If one desires to archive their saves, they can always do that outside of the game itself. For those who wish to savescum anyway, they can do the same.
I'm mostly talking about save systems in a vacuum, but looking at the reality, I can somewhat agree with you. As I said, in a perfect world, devs would just simply ignore idiots misusing the system, and wouldn't let them have any impact on the game design itself. But of course there is no perfect world, and since they seem hell-bent on saving savescummers from themselves, straight up preventing savescumming is indeed an infinitely better choice than designing the game around it. So yeah, realistically speaking, I can agree that pushing for ironman/limited saves everywhere, is probably the smarter choice than defending free saving, if we want good games in the future.