Should Blog comments be enabled or not? It all depends on the purpose of the Blog. Most Bloggers have a need to express their opinions and exchange thoughts. A blog with comments enabled will allow your readers to post their comments. Most Blogs allow you to adjust the settings so that you can approve them before the world sees them. In other cases, some Blogs may not require the comments to be activated. Just keep in mind that the important thing is really the purpose of the Blog. You might be surprised by the positive impact that comments enabled will do for your Blog.
On the other hand, what happens if the worst scenario in the back of your mind may happen? Somehow someone does post something totally inappropriate, rude, or insulting.