I would never impute bad faith to anyone without clear evidence, so let us accept that Mr. Sircom is sincere in his belief. I think it's worth looking at what he actually says. This seems to me to be the key paragraph (the added emphasis is mine):
I have performed such comparisons on several occasions and in a number of different contexts, and I've begun to conclude there is no simple answer. In many cases, the sound of disc and computer audio are on a par with one another. In some cases (and even, with some listeners) computer audio sounds distinctly more natural than CD, and also the reverse is true. But once you breach that top-end barrier, the more people you test, the more you come up with preferences toward the spinning disc… even under blind conditions. In fairness, these differences are fairly subtle, and I still maintain that well-handled computer audio is not 'ruined' next to spinning disc, but the preferences are distinct and consistent.
So, if I may paraphrase: until you get to the highest of the high end, there is no clear preference either way. Some prefer computer audio, some prefer CDs, some have no preference. Nothing is conclusive. This is perhaps not surprising.
But then, suddenly, when one breaks into the rarified air of the truly high end, there is a preference. I can't say with certainty this is wrong, but I'm sceptical. How clear is this preference? Is it statistically significant? Are the test subjects being unwittingly biased or influenced, even in supposedly "blind" (though presumably not double-blind) tests? Could this conclusion not be an example of unconscious "confirmation bias" - i.e. seeing evidence that supports your conclusion, disregarding evidence that doesn't?
And there's a commercial factor here. The manufacturers of CD and SACD players tend to advertise in the pages of audio magazines. Apple, Dell and HP tend not to. I am not challenging Mr. Sircom's integrity in the slightest; nonetheless, he has a clear commercial interest in maintaining the spinning optical disc as a viable music medium. And I do believe that such interests do have a way of shaping and influencing one's beliefs, even where one is intending to be objective (as no doubt Mr. Sircom is).
At the end of the day, if multi-thousand dollar or pound CD players truly sound better than a digital music file from a computer (run through a high quality DAC, of course), there has to be a rational explanation, given that the bits are the same. I'm still not sure what that explanation would be.