What is blogging, exactly?
Blogging is just a different way to build a Web site. Its content is organized by the date/time of its "posts," which are what blogs call "Web pages" (even the word "posts" suggests time-sensitivity).
So why did it become so popular? It was not due to the journal format. Nor was it the heavy link-exchanging that bloggers do (Google discounts their importance).
It was not blogging itself at all. Instead, it was a technology called "RSS" (enables visitors to subscribe to your latest content) that caused blogging to enter the mainstream.
Since blogs are essentially about your latest post (few read more than that), RSS was the missing ingredient. It alerts followers when you make your latest post. That is critical for blogging, which delivers time-sensitive info.