There are literally millions of blogs in the world. Some are small, others are quite well known, and a few make tons of money.
So if you visit plenty of blogs, at some point, you're going to end up seeing a lot of the same people. Knowing that, I'm very surprised that one blogger would publicly bash another. This includes complaining about how a blogger writes a review, how she's putting on eyeliner incorrectly, is a horrible person because of her political views, or that he or she is fat and needs to lose weight. Someone is going to see that post that you know, or even worse, you may see it yourself! This causes tears of hurt, or a lot of back and forth cursing throughout a blog between people. As I scroll through those posts, I end up feeling embarrassed and sad. I don't get it.
As bloggers, we love being stalked because of what we write about. But while flaming wars may be interesting to some, stalking someone on their blog for the purpose of verbal attacks, or using your own blog to bash another blog just seems mean-spirited to me. We may not always agree with a point of view, but kindness is key.