I'm not sure about Mc buyers, new or used today but, years ago persons who were willing to part with the premium to purchase Mc did so as it simply reproduced a closer presentation than other brands and did not market hype. It had little advertising, did not join in the spec wars, would decline requests for review samples and relied more on word of mouth than any other form of marketing. The company did not for the most part cared less about what the other companies did than whether a part put in the unit was within design spec.
As a dealer we had 2 types of persons, those that came in for a stereo and those that came in and wanted a Mc setup. The latter usually came in after hearing a friend's system. Many were Doctors, Lawyers, university professors, actors, musicians and many other who usually attended live performances on numerous occasions. Yes, well heeled and usually above average earners but they also knew what sounded more closely to what their ears were attuned to. They did not need to justify or show off their systems. I'm not sure that this still is not the case.
Some of us do enjoy flirting with other brands and talking about equipment but more oft than not, we are get more excited about buying a good record than about buying a new interconnect.
FWIW, some decades ago I decided to quit equipment rolling and find a system to keep in place for life and after going through many pieces, models, brands and systems, I decided on a Mc system and it is still my main system save the power amp that I upgraded only to get the larger Mc of the same vintage. I was lucky in being able to audition more than probably most as I owned 4 stereo stores and anything I was not a dealer for I could just call the manufacturer's rep and ask him to send for evaluation.
If this sounds a bit snobbish, it is not meant to be. It is not much different than asking why a Rolls Royce owner is not discussing the Rolls on the auto site in the same way most talk of their GTOs, Corvettes, Malibus, Infinitis, etc.
Now, if you stroll over to the Mc group, you'll find them very passionate when it comes to Mc units amongst themselves. Oh, and yes they worry about tube rolling, what caps to use, if model A is better than model B but not as interested about whether brand x is better than Mc as they already know the answer to that in their eyes otherwise they'd own brand x.