I'll make my position clear, I'm in Elsie's camp. It's not a question of judging the value of a song, but of simply understanding one another, without precise definitions to the words we use, we might as well skip the ambiguities and resort to grunting, snorting, stealing and raping.
Someone made references to the way jazz has accomodated so many styles; as a jazz fan, I've gotta say, it's really annoying to have to ferret out what someone means when they say "jazz," For many people it's just three chord soft rock with a saxophone. The word is losing its purpose, definition of a musical form.
There is another thread about ideas for a mudcat discussion forum, this may be a good place to troubleshoot ideas for that. I love many of the songs that are labeled "folk," but I bristle at the misuse of the term because it makes it all the more difficult for me to converse with people. Fuzzy definitions are for fuzzy thinkers.
Perhaps a category known as "post folk" to reference music done in the folk style by the modern singer/songwriter. Not much of a definition, but you get the idea.