KiwiPolitico a few months back tried to put together a list of the "coming generation" of left and right public intellectuals in New Zealand. The lists are embarrassingly thin, with minimum standards for inclusion very low by international standards.
A year ago, I'd have said Denis Dutton (for the right) and Jim Flynn (for the left) were the only picks worth noting in New Zealand. Both have built a substantial body of scholarly (not necessarily academic) work and have built on it to engage the debate in public forums. That's the general minimal condition for a serious public intellectual. Internationally, you'd think of, on the right, Chris Hitchens, Theodore Dalrymple, Greg Mankiw, Tyler Cowen. In the younger set, Will Wilkinson's excellent. There's nobody in New Zealand who hits that kind of bar on either the left or the right.
First, thin markets. The very best small number of people in a big country will be better than the very best small number of people in a small country. That's why India's always surprised (or at least the lunchroom tells me) that New Zealand manages sometimes to field a non-embarrassing cricket team despite having a population roughly equivalent to a small town in India. But most kids here grow up holding a cricket bat and despising eggheads.
Second, academia's usually the first place to look for public intellectuals. You've a set of folks who are paid to spend all their time thinking; it would be surprising if a few of them didn't build on that to enter debate. And a few have. But that kind of work gets low to negative weight by University higher-ups: for promotion (Dutton did not make Professor until his 60s), for research evaluation, for salary negotiation. I'm going to put up the blog for the 2012 PBRF research evaluation. But if I had redirected my efforts from the blog to publishing 3-4 really crappy articles in really crappy journals that nobody but the referees would have read [Offsetting's well north of 200k visits and 300k page views, adding RSS would at least double that], I expect that the PBRF panel and my employer would have been happier with me. One of the folks over on the admin side who tries to encourage more adoption of web technologies says other academics he's encouraged to try blogging have always replied "Does it count?". This blog perhaps survives through slack in the principal-agent relationship, though is well supported within the Department.
Third, small markets mean no real think tank environment - the other typical sponsors of that kind of work. Small markets mean few patrons, and it's tough to get public intellectuals without patronage. Roger at the NZBR works hard to make sure that the pro-market folks at least know who each other are, but they're not really resourced for patronage.
So who gets picked in the Kiwipolitico comments? A few newspaper columnists the depth of whose work is limited by the thinness of the NZ market for serious essays, some bloggers, and an academic or two. Lots of folks on the lists are disseminators rather than generators of ideas; lots of others who mostly run play-by-play on local politics. Both are important roles, but it's not really what we expect from public intellectuals.