I think your premise is erroneous, except for the parenthetical fudging that they might not "admit to it". About the same time that this thread was started, I experienced a paradigm shift. I'd been building Heathkits since the early 70's, adding mid-80's Luxmans to the mix, finally going digital HT in '99. Sent one of my kids to Caltech with a stack of music CDs that I'd made for her (Ella Fitzgerald, Oscar Peterson, Miles Davis, Puccini, Barber, Ralph Vaughn Williams). When she came home and listened to the new digital HT system, she was appalled, "Why does that sound so different from what I hear on my own system?" I'd sent a mid-80s Luxman receiver with her to school. That started my own return to analog and a search for great quality. Like I said, it was just about the same time that this thread started. Since then, I've gone through a number of different manufacturers of electronics and speakers, with the constant itch that we all have to trade up all the time. That itch is finally gone, after over fifty years. I'm using Mc C2200 and MC452 on Revel Salon 2 speakers in one setup, Mc C-22 and bridged MC275s on JBL Everest DD67000 in another setup. Late 70s Luxman separates on JBL L-300s in one bedroom, Mc 4100 receiver on JBL Project Array 1400s in another bedroom. Mc 117 receiver on ProAc Response 2S in our travel trailer. The only other electronics that I found pleasing over a fairly long period of time were Mark Levinsons. Getting back to the original question of this thread, I suspect that there's little mention of Mc on audio threads is that there's a very high level of satisfaction with that gear when it's carefully chosen. I have had a few less satisfying experiences with their gear - MC7270, MX134 - but after only a handful of missteps, I can say that I am perfectly happy with McIntosh. Music is playing almost constantly on one system or another, sometimes on all of them at once, linked with Bluesound.
We have a second house, a frame farmhouse built in 1900. Because of the age of that house, I am setting up a dead stock Dynaco system with PAS3, ST70 and A25 speakers, all of them in mint condition. I acquired the speakers ten or fifteen years ago when I puchased some other Dynaco gear and have only just now discovered that they are brand new. They were an afterthought, offered to me when I bought the electronics. I wasn't really interested in them but the seller wanted to get rid of 'em, so I added a couple hundred for them. Since I wasn't interested, I stuck 'em in the store room, and there they sat until a few days ago. We have finished a restoration of that old house and it occurred to me that a really old middle of the road system would be perfect for it. I remembered those old speakers and dug them out. When I opened the boxes, I was shocked to see that they've never been removed before. This stuff is really, really fun, isn't it?