Absence of major publishing houses in The National Book Critics Circle

According to The New York Observer, The National Book Critics Circle, an organization made up of about 700 active book critics, announced on Saturday the finalist pool for their end-of-year awards and the Poetry category did not include a single book published by one of the major houses this year.

The nominees in the poetry category included:

Mary Jo Bang, Elegy, Graywolf; Matthea Harvey, Modern Life, Graywolf; Michael O'Brien, Sleeping and Waking, Flood; Tom Pickard, The Ballad of Jamie Allan, Flood; Tadeusz Rozewicz, New Poems, Archipelago.

Is this a trend, or a fluke?