Seven of the top ten are decidedly Calvinistic, most aggressively so, (Interestingly, Michael Hyatt is Eastern Orthodox (of the Antiochian Sea) which is fascinating. Scot McKnight is hard to categorize, but not Reformed.
Now why is it so hard to categorize someone who is an Anabaptist Anglican type?
My observation: Early in the blogging world, say 7-8 years ago, the blogging world was much more into emerging blogs and, at that time, many Calvinist leaders were wary of blogs, bloggers and the distraction blogging was. The tune and tone have changed.