It's not a scam. Naim amplification topology is such primitive rubbish, it has to completely rely on components quality, precision and matching to work at all. This is why they handpick everything at the factory. Problem with those tantalum caps they use is that they drift from their values over time and even explode sensationaly. I'm sure the new Kemet SMD ones are not as bad as the old ones, but still it is their thing they do. They still use them because they have much tighter tolerances than electrolytics. The Class B circuitry is always on the edge of working and not working, balancing act of such magnitude that hearing washing machine or transformer hum is deemed acceptable compromise.
Naim amps need regular maintanance to check and keep everything withing design tolerances. Again, it's not as bad as in the early days when components were generaly of lower performance than today and when Naim was a cottage industry business with significantly lower build quality than big corporations.
Why do the customers tolerate it? I think they even welcome it. It's a business model and a culture buble. I wont say a cult, but narrower interest niche in our hobby. Naim can build spectacular amps if they want to, but the customers want the whift of Julian's cottage industry days. They want the good and the bad. None of that flat, neutral, smooth or warm nonsense.