Or, rather, it can take more work than you'd think at first.
I was thinking about this as I read Jeff's post on Apparently Bloggers Aren't Journalists. I always think I should blog more frequently, but I'm very weary of "me too" posts or making mistakes in what I do. So typically I will stick mostly to interesting product releases, random personal thoughts that are linked to programming, or edutainment pieces about how to use a particular technology or a gotcha here or there.
Writing a sample-ish post takes some work, but is straightforward: an idea comes up, it goes to the queue, and when I have the opportunity I code it, test it, and then write about it. Sure I might be able to have a shorter process, but taking the time to properly make sure that everything works makes the post more valuable, or at least not harmful.
Opinion pieces are also hard. Come up with the idea or thought, but then be able to back it up. And coming up with a way to back up your opinion isn't trivial. It requires doing homework to make sure that the thing hasn't been posted to death, that you have a factual basis for your opinion, and understanding what the margin of error is. For example, I am more likely to have a wrong opinion about up-and-coming stock picks than about up-and-coming data access technologies.
But in the end, I am happy that the content I post on the Internet is of zero-or-positive value. On the other hand, I would be very disappointed in myself if I was spreading mis-information, and even more so if it was a result of a failure on my part to do a reasonable effort to check what I'm posting.
Which is a randabout way of saying that responsible blogging can be a chunk of work, and hopefully not an excuse for my being so random in my posting.