Widebody good, narrow body bad - why ?
Dotted around the web, there seems to be a fairly common opinion expressed, that when flying more than a few hours, one should prefer to fly in a wide body (i.e. twin aisle) plane instead of a narrow body (single aisle) plane.
I'm specifically excluding the A380 and 787 from this question as they are a far newer design than the vast majority of planes. Looking only at aircraft in common usage and not about to be sent to the scrapyard, narrow body in this context means something like the 737, 757, or the A320 family, while widebody would refer to the 747, 767, 777, A330 and A340.
I can appreciate there is often a difference in the premium cabins, but am puzzled as to why this perception exists for the seats in economy. Is it that people want the seat-back TV which narrow bodies generally don't have ? The higher cabin ceiling of a widebody ? Or something else entirely ?