Can you afford not to blog?

I was reading the NYTimes' day-after analysis of the National Security Agency's surveillance program decision from Judge Anna Diggs Taylor and was struck by how widely the columnist used bloggers as sources quoted in the article. By my count the first three quotations from a private attorney and two law professors, are referenced as bloggers.

Question: Have we reached a point in some fields where not having a blog is really going to limit ones influence and cut into their business/influence, period??

I think the answer to the question is clearly yes and I'm just uncertain and just don't have the breadth to say exactly what fields are most imminently impacted. In the legal field, it seems like if you're a law professor who really wants to have influence outside the small law review world, i.e. the mainstream media, you need a blog. Second, I think if you're a legal consultant, you need a blog. Those are the two that jump out at me in my industry. Speaking as an attorney in private practice, I could go on about the benefits of blogging but I won't. What I will say is that I don't think a blog as a private practice attorney is a "need" yet. However, I would say if you want to be someone who the mainstream media contacts and have some press relationships regarding particular subjects, having a blog may be particularly critical.