I am in support of being a able to blog, and not just because I'm supposed to be. :)
I think it's a great responsibilty to carry on a properly done blog. As a blogger, you have a responsibility to your readers to post timely and carrying interesting, possibly informative content. It allows you to utilize a range of skills and apply them to something you love. It's free and rewarding. And if perchance, your blog takes off, you may gain money from advertising.
Video blogging, or vlogging, is possibly the most difficult way to blog. Not only does it require more forthought than a written blog, but it demands that you have an ability to present yourself on camera. You need proper delivery of your words and gestures. As the most successful vlogs use effects and basic graphics on screen. Not to mention, the time-consuming proccess of video editting.
In short, in most cases, no matter what the content, the act of blogging is a productive use of time.