But it's also most often used just as a pejorative to describe anyone whose activities you believe to be 'least useful.' I mean, you must admit. Does anyone call himself a pundit? With happiness at the prospect? Two hundred years ago, they'd probably have called Thomas Paine a pundit.
Or a blogger.
*is gleeful at the prospect of a blog at www.commonsense.com, written by Thomas Paine*
I agree with c_b, that punditry refers to what pundits do, as opposed to being a collective noun. As she already pointed out, carpenters do carpentry; similarly, devils engage in deviltry and bandits are involved in banditry (really; I looked it up).
It remains unclear whether pandits conduct panditry, or whether hobbitry is an accepted term for describing the behavior and activities of hobbits. But we know that idolaters commit idolatry. And finally, we know that the word to describe "the attitudes and behavior of a narrow-minded, self-satisfied person with an unthinking attachment to middle-class values and materialism" is Babbittry.
One might, I suppose, refer to the entire class of bloviators as the punditocracy, by analogy with words like bureaucracy and aristocracy.