Is there a profession that DOESN'T need a blog?

I started my blog because I love Penelope's posts. I agree almost 100% of the time with her. However, I'm wondering if I need a blog. I'm a high-level executive assistant, in the entertainment industry, and I've been lucky enough to be headhunted by Fortune 75 companies through word of mouth or finding my LinkedIn profile.

The question I'm really asking is, "Do I need to blog?" because I'm at a loss of what to write. And is there a point in expending so much energy in a life-long project that may not have any positive benefit? I feel like I may not fit the typical demographic of bloggers. I like being a career executive assistant, I like working from nine to six, I even enjoy overtime as long as it doesn't top 55 hrs a week. And I feel as though most people who have a blog want to be freelancers or their own boss, which I don't.