If that is the case then Adobe are at fault for not delivering a package that works as well as expected for people using "out of the box" computers from Dell, HP, Apple, etc. Similarly, fault would lay with hardware manufacturers for not delivering systems optimally tuned. If hardware vendors delivered systems to the public in such a poorly configured state then you can be sure that websites would review them badly and slowly but surely, reputation and sales would suffer.
Whilst you may enjoy in tweaking and measuring the performance of everything on your system, the average person isn't going to - and nor should they need to. And nor should they need to engage someone to help them tune their system - if they want to fine, but it shouldn't be necessary as it should just work out of the box and work well.
Thus I would hope that the testing Adobe does uses "off the shelf" computers from various companies and evaluates the performance of their applications in that way, rather than using custom builds that do not reflect what the average consumer uses.
Now it may be that in their testing, Adobe have made various assumptions in their application environment that actually match up very well with what people here are doing or that some settings (such as the automatic update of XMP files) are set the wrong way. I don't know, so I'm just guessing. Similarly, there may be changes in the application that for one reason or another slow it down in ways that they didn't expect.
But what is very clear from various messages in this thread is that Adobe have some homework to do because they've created performance issues that faster hardware is only going to hide for a short period of time.
1. Yes and no. Obviously they can always do better, and it appears in this case particularly. But in general, and I've used this analogy before, image processing is a very hardware intensive task. And so is gaming, video editing, and CAD/CAM, but these three areas have long benefited from custom builds and builders with specialized knowledge. Where before, most image editors processed one task on one image at a time, LR is now doing much more. From this perspective it doesn't surprise me at all that image editing at the bleeding edge now needs like attention and expertise.
2. Again, I'll invoke the gaming analogy. With games you don't "need" a powerful system, you don't need to hire a builder, etc, etc.. but we've long accepted that performance is directly linked to your system. In Lightroom image editing as now reached this stage. Where we're being let down from Adobe, is they haven't written the code/processes to take advantage of the modern GPU, SSD's, RAM, etc, nearly as much as they could have. The should. And when they do they'll probably make a huge deal of it and double the price..
3. I think we would benefit either way. I'd like to see them test/benchmark using "levels" of systems. Say, an 3770, 16gb of 2133, 300mbps R/W SSD for system, 100mbps R/W data, hybrid catalog, 6800/560 series GPU at one level, a dual core i5/4gb laptop on another, and so on.. I'm sure we could easily agree on the necessary levels and where to place them. Then someone would know what to expect for a given "class" of machine vs. a specific model. And I'd bet the farm we'd have scores of independent bloggers, builders, etc.. verifying their benchmarks one way or the other and/or coming up with their version of upgrade and what difference it would make.
We need to grow used to the fact that image editing requires considerable hardware, and that increased performance is directly tied to more powerful hardware. Image files are getting bigger, more of us are taking on video, and in general improved software in the sense that we're offered functions not previously offered.. ALL takes more hardware. More, it requires more hardware working together which makes the "build" and "tweak" all that much more vital.
It's been an interesting educational thread..