I agree with you that blogs, or other web applications, are not substitutes to traditional media. I see them more as alternatives.

Like online shopping is not meant to replace physical stores but to offer an alternate mean to reach customers, especially new customers physically distants, blogs are not meant to replace newpapers or magazines but to offer an alternate way to get information on specific subject matters.

I own a car, does that mean I can't walk to the convenience store anymore?

Why keep only one when both can be useful?