Come on. If this weren't ER would you really be giving the developer so much slack?
. . . these are issues that have been in every FS game in modern memory and they STILL refuse to address it. As good as a game is, if there are performance issues that break immersion it should be roundly called out.
And "compromise their vision" - hooboy. The last gen versions of this game exist so clearly they are ok tweaking graphical fidelity to get the game running. So they excuse is out the window (and doesn't explain why a simple frame rate lock isn't an option for consoles or why the performance issues exist on PC with seemingly unlimited hardware).
Their engine isn't brilliant, its a fair point. However you can't really expect every team to produce results of equal quality and performance. Sure, you could argue that say their tech isn't nearly as good as say, Remedy's. But by the same token I think you could argue that FROM do a bunch of things in their games much better than what Remedy does in theirs.
I also think you kinda prove my point by referencing how this is pretty much expected for a FROM title. It is simply a product of what they value in their work. For example: Blighttown. That area ran like shit at the time of its release, and so, that they chose to leave it as-is, and didn't redesign the area (specifically the descent down into it) in order to mitigate the performance issues can not be construed as anything other than a considered trade-off.
This is what I was getting at by a refusal to compromise the design goals.
Just think about how variable resource/draw-load is on their games. Apart from the normal pretty big fluctuations in drawing the world, there's also a pretty considerable additional level of variance due to the need to support all the spells, effects and weapons of both the player and co-op and PVP partners, enemies and whatnot.
Never forget that if you start down the path of chasing a "perfect" frame-rate you need to factor in the worst-case load scenario at all times! Now this isn't impossible, but obviously the less constrained things are the harder it gets, and possibly even more dangerously the bigger the delta between "normal" and maximum load, the harder you need to globally cut-back in order to ensure you always stay in budget.
Bottom line: they basically accept that taking a hit on consistency of frame-rate is the lesser evil when compared with making tough cut-backs in order to offer the smoothest performance. That's their creative choice, and how they roll.