Inteligent design is a challenge to the most basic assumptions of deterministic materialism.
They cannot defend or maintain their assumptions in the face of new evidence that the Universe is obviously designed, so, in a sort of reverse-Gallileo scenario, are resorting to simple dogma and ostracism to maintain the status quo.
They have become the New Inquisition trying to rein-in new scientific inquiry that does not share their paradigm lest it go where they wish it not to.