OK, I'm an audiophile. I admit it. But for me to go in and compare two different speaker cables in a system and, just as importantly, in a room I'm not familiar with is a tall order. There are simply too many sonic variables that are new that would preclude me from reliably discerning the subtle yet often very meaningful differences cables can make.
Now, put me in front of a system that I'm very familiar with and I'd be happy to take that test. I think the approach taken in the test, while on the surface seeming very valid, just doesn't work in trying to identify the fine differences cables can make. I agree the differences between speaker cables are small on an absolute level (and much larger for interconnects in my experience), but once you're happy with the rest of your system the right cables can really bring things together (or not). This is something you can only assess over time in the context of your own room, system, and tastes -- not something you can readily assess in a completely unfamiliar situation.
One analogy to the non-audiophile world might be like tires on a Ferrari. For the person who views cars as transportation they might be just as happy (or even moreso) with Sears Roadhandlers on wet roads as with a $3000 set of performance tires. But being able to compare the two over time and through a variety of situations the differences become much more meaningful and significant. This, to me, is very similar to how cables become imporant within the context of an audio system.
Then again, I can certainly see that it's much easier to just dismiss cables as a scam. To each his or her own.