I know a few of my classmates think blogs are a waste of time. Some complain that nobody reads them, others think it's an outdated format, a couple don't want to contribute to the growing amount of crap already on the internet, and some just don't feel like it.
There's not much I can say about the don't feel like it crowd; however, I do agree with one criticism: a lot of people do write at least some crap - myself included. But that's just why blogs are important for this program. You don't become proficient at a skill by avoiding it. History is a literate discipline, and unless you plan to be a ticket-taker at the local heritage centre, you will likely write in some capacity during your public history career. That writing might be on text panels, brochures, or in magazine articles. It might be part of your job or a supplement to your income. And if you don't practice, you aren't going to get better.
Poor grammar on a text panel will get your museum a bad review. A sloppy or ineffective style on a brochure might mean no one will show up to your event. And an inability to come up with a good angle will quickly get your magazine article shuffled to the bottom of the pile. So, why not practice now?
Chances are, you won't write anything award-winning on your blog; most of your thoughts won't be as complete as the Cliopatria "best post" written by a member of UWO Public History last year. But, a blog offers you an audience - albeit modest, and a chance to practice your writing. No matter how professional your clothing, or how friendly you are, there's a good chance you will be hired for your ideas and your ability to communicate them.
Chances are you haven't mastered it yet. I find it amusing every week when a few of the teaching assistants in my seminar class complain about how terrible their students' essays are, and then these same teaching assistants proceed to read aloud a terribly written presentation, word-for-word from their notes. I can only imagine our professors, sitting in the lounge, are making the same comments about the overconfident Masters students' poorly written papers. You can always improve.
And, while you might think it's a waste of time to blog because nobody reads it, who, I wonder, was reading your academic essays? Was that a waste of time? If your blog traffic is anything like mine - which is nothing to brag about - more people have read your blog in the past month than all the people that have ever read one of your academic history essays. While I concede that what you write on your blog may never get you a job, or even an interview, it will give you a chance to work out a few kinks in an important skill. For that alone, the blog is not a waste of time.