I get tired of it too Jax, and I'm not saying that because I'm a retailer (removes retailer hat).
As many will know, I've always been an advocate of driving speakers properly (even if some others round here aren't), and I've heard the differences that an amp that's not up to the job can make. If people are trying to tell me that a Pioneer A109 and a Bryston BP26/4Bsst2 sound the same, I'll laugh at them.
DACs. Maybe the actual chip incorporating the gubbins that changes digital to analogue sound similar, but there's many other parts of a DAC that will change the sound, like the transformer, circuit layout, and the analogue output. Early Naim CD players always taught me that it almost doesn't matter what chip is being used, it's how you use it that makes the biggest difference.
I think with cables, some just see a lucrative market that's making millionaires out of those feeding off weak people duped into thinking that cables don't make a difference. But, those that have witnessed a cable making a difference know better. See yourself as blessed - some people can't tell the difference. Although, I appreciate that some just refuse to believe they can make a difference just on principle - I can dig that, that's their choice. Whether you do or don't, it's no skin off anyone's nose.
Electricity! I'm no electrician, but I can see the difference between a projector at home and at work. How is that? It's the same Bluray player. It's the same cable. It's the same PJ. So why does it judder at work and not at home? Why is there a grain in the picture at work that doesn't show up at home? Only one answer there.
I think some look at the basics - or the numbers - and say, "nope, that's not possible. There's no logical way there can be a difference". But they don't bother listening. They're too tied up in the basics that tell them there can be no difference. If there was no difference between a cheap amp and an expensive amp, why would I pretend there was? There will be some now saying that I will because I'm a retailer. That's not a good enough reason. If I tell you that this £5k amp is better than this £200 amp, what happens if you come along for a demo and you think there is no difference?
Maybe WHF can do a TBQ and have a cheap system and a much more expensive system, and the panel could hear both through the same, high quality speakers, and see if they can pick out which system is which. It should be a foregone conclusion, but maybe we'll be surprised. I'll sit in on that one