Factions, Groups and Schools

First of all today, here's a quote from Tom Chivers' guidelines for authors on his excellent new Penned in the Margins website:

"Factions, groups and schools are for the history books"

In the meantime, however, over at Poets on Fire I encountered a link to the following article, titled "The New British School (from an American perspective)" I have to say I very much agree with Tom on this: factions, groups and schools are only useful for literary historians. Even then, they can lead to crass pigeonholing. So why are they still invoked on such a regular basis among contemporary poets and critics?

These terms are befriended by poets and critics, often with a academic background, who feel the need to structure their views on their own poetry and other people's work within the same kind of framework they've always been encouraged to use in their studies. Nevertheless, I'm convinced that the writing of poetry should build its foundations on reading, not on study.