I think for a lot of people it's simply the practicality and expense that holds them back. My guess is there are many audiophiles out there who acknowledge the clear superiority of multi channel playback, but can't implement it due to space limitations, budget limitations,
I'm on your side with the general gist of your post, but I think you give too much credence to the excuses. You are talking about
audiophiles...
Expense. Even low-budget audiophiles don't usually buy
the cheapest amps, speakers, and players on the market. I bet you half a brisket that an excellent AVR is available for two thirds of what these hesitaters paid for their stereo amp, and for half to one third of what they are seriously thinking of spending on their
next upgrade stereo amp. And speakers: someone has to tell them, if they will listen to anyone who doesn't have
Hifi Guru printed on their baseball cap, that they don't have to buy three or five more of the two expensive speakers that they currently own. Good bookshelf speakers, chosen to blend well with their current stereo speakers, are definitely there to be had at every budget level.
So, if these guys, as you say, "acknowledge the clear superiority of MCH", I almost guarantee that they could sell off their stereo gear (which is often on the list of wannabe audiophiles and would sell quite well), then think of the budget they would have put into their next stereo system, and for the same or even less money get a very nice MCH system. The expense is effectively zero as an exchange, and can be quite small as an add-on.
Impracticality aka space. No doubt, there are some audiophiles whose better half won't give them an inch and won't miss an opportunity to complain about even the modest space demands and undecorative effect of the current hifi. Somehow a giant black rectangle on the living room wall is no problem, but a hifi with about a quarter of the TVs visual area is a big drama every day of the week, and upping their visual area to half the TV is the end of the world. These audiophiles have got bigger problems than surround sound and had better forget about it and try to survive. BUT. For the majority of audiophiles complaining that impracticality is the issue, it actually is surmountable, negotiable, and worth doing. Cables can be hidden. Speakers can go in-wall or on-wall and not take up any floor space, and be a blended colour if necessary. If the listening couch is hard against the back wall, then that's not right for stereo either, and since audio compromise is a normal part of this household, then the surround speakers can go on the side walls each side of the couch, or even in or on the ceiling. Yes it's not perfect, but neither is that couch on the wall for 2-channel, and ceiling-mounted surround speakers will still provide some positives after stereo. It doesn't have to be 11+ channels: just the 5 yields a big benefit.
So, in the end, I think it is their
anti-MCH bias that is, perhaps even unconsciously in some cases, the spur that leads to their forming a false impression of the impracticality and expense of MCH. And that bias means they are not upset about it: they are
relieved about it.
cheers