I agree. A blog is nothing more than a magazine. If you think you can and want to compete with all the other online magazines that cover the same topic as you, then don’t do it. To give a little more detail, a blog is a useful tool to get more people to your web site. This is only true however if your blog is unique and gets ranking itself. If not it is a money pit.
For example my business is a local pressure washing company. First thing is that pressure washing is a low interest area and not conducive to blogging in the first place. Second thing is it makes no sense to try to make Apex Pressure Washing blogs rank since a] nobody is looking for articles about pressure washing, and b] i wouldn’t want to spend what it would cost to get it to rank nationally.