I think many people who remember the 70's had bad experiences with quad, what with primitive decoders, some pretty cheesy records, too many competing systems, and poor set-up. So far I have two friends who thought quad was a total failure, "just a fad", until they heard our local oldies FM station through a DPL-II system.
(I don't use a center speaker, so yes, by speaker count, it IS quad) Younger friends who barely remember (or don't at all) vinyl records have commented on how much better FM stations and some CDs sound in my old truck...and it has just a passive decoder! I think if we avoid the term "quad" or "surround" when first exposing strangers to our passion, maybe just sort of "sneak it in", we may find that with today's great technology (or the best of the 70's, you guys with QSVM or CD-4 or Tate rigs!), there IS an un-tapped market of young ears eager to experience the same thrill we did so long ago.
Excuses? I heard them so much back when I was pushing Q8 and the EV system for Rat Shack, and probably the strangest one was "more than two speakers is only appropriate in a theater!" That customer didn't know it, but he gave me a great sales tool! I started asking folks if they had seen "How the West was Won" at our local Cinerama house, and if they had, asked them what they thought of the multi-channel sound. Then I just told them, "The whole idea of Quad is to let you have that same kind of realism in the comfort of your own home." Today of course, we could make the same comparison, with most theaters showing some kind of surround-blessed films. Other than that, I just turn on my rig, and let the sound do the talking to the un-initiated or un-interested.
If sonic realism, and the pursuit of it is a "fad", so be it...it is one "fad" I hope lives as long as I do!
TB