There are very few blogs dedicated to webcomics. (I list them in my right margin.) People think there are lots of us because there are lots of comics blogs, some of which do include discussion of webcomics. The majority are focused on Batman and Iron Man and friends.
There are also lots of dead blogs in people's blog roles. The fact they they persist, undetected by the blogger, says a lot about that person's sincerity. They don't even read what they recommend. Some of these blogs have been dead for two years!
With zhi apparently gone, the surviving purists are:
Some have a limited focus, just offering reviews, sometimes mixed with essays. Others are more focused on news.
Another thing that makes it seem like there are more than there are is that people are always starting webcomics blogs only to wander away after a few months. Here's a typical derelict blog. People who slather their name all over their blog seem to give up first.
Even some of the blogs that have been around for a while have a tendency to go weeks at a time without updating. About half the blogs in my list have no update schedule.
Nonetheless, if you're involved with comics in any capacity, you owe it to yourself to examine this list and find a few to visit periodically. I find it worthwhile to have a sense of the major threads running through the world of webcomics.
Keep in mind, if ever there was a thankless task, it's blogging. Forget the hype: it's really for losers and fanatics. I do it to keep my writing chops up, to learn, and to think, but it does almost nothing to promote my comics or deliver me feedback. It's kind of an idea test strip for me, and the stuff that looks good a week later gets moved onto my web sites.
If, as a reader, you want to support a sophisticated world view of web comics, give the blogs some attention, especially the ones who don't have another web presence to fall back on. I concede that those which can't attract readers might as well throw it in, but the greatest barrier to blog reading is the tangle of dead and off-topic blogs burying the functional ones so deep even Google can't find them.