I kind of see a parallel to Jones bikes in that both are different from the mainstream. Except Rivendell is "different" just because that is how bikes used to have been made. You basically buy it to be different, not to have a better bike. It is like restoring an old bike minus the work to restore.
Jones bikes on the other hand are different for the sake of being better and throw old convention over board. Jones embraces new technology and standards (29+ tires, disc brake only, modern hub spacing) where appropriate. Rivendell seems to ignore new technology... but not because the old is better, just because.
More knowledgeable people may disagree... but it seems the market has spoken.