My personal response to this (very old) thread would be in a similar vein to
something I have written recently elsewhere.
I actually rediscovered this thread (which predates my joining of the Downs!) by trawling through the old archives in the Mirth forum and found a reference to it--which is basically right up my alley.
In response to the original question, although I think that "high, purged of the gross"
is something that I specifically strive for, at least in some parts of my life, and although I definitely would attribute some of this to Tolkien's influence, I do NOT think that this is necessarily a fandom-wide response.
For one thing, you have only to delve into a fanfiction archive to realise that either "high, purged of the gross" means different things to different people, or it isn't a goal of a number of Tolkien's fans: and we're not talking just about moviegoers here. We're talking about Silmarillion fanfiction from people who have clearly spent as much time on the HoME as I just did in the archives of this forum. That is not to say that fanfiction is written by bad people, but there is ample evidence that aiming for any sort of moral height is not to be found in this significant, invested part of the fan community, and a lot of the time their work may be spent putting elements of the gross back into the story.
As for the Barrow-downs, while I do think we have our own distinct culture that aims for a version of Highness (and our sternness regarding the Off-Topic could be considered a self-purgation of a type of self-defined grossness), I'm not sure whether it's safe to say that we necessarily take this to heart in day-to-day life. It's probably not fair to define anyone's life by the ebullience expressed at a BDer moot, but it's definitely true that a high stateliness is not the first mode expressed at one. Actually, that makes me wonder if it's even fair for me to say that "high, purged of the gross" is something I can be said to aim for in my own life, since one of my favourite BDer Moot activities is shocking people with just how much more irreverent I can be in real life than online.
My chief response to that self-generated line of thinking is that the key word in this phrase of Tolkien's is "purged." After all, he isn't saying that his characters exist in a world that doesn't include the gross, but that he is writing a tale that purges this element from the telling. It is an aesthetic decision to remove this, an aesthetic decision I am inclined to appreciate and to at least aim for in written discourse... but I don't know that it informs my non-written life as much as I would want.