Who are we to tell someone whether or not they are a journalist? Just aspiring/employed media journalists vary in talent and ability, so do aspiring or paid bloggers. By definition, a journalist is "a person who engages in journalist; a person who keeps a journal". A well-respected or notable journalist takes talent and experience, but casual bloggers, by definition are journalists as well.
In my opinion bloggers are not journalists because, first of all bloggers give out the information for free. In the other hand journalists do it for a company and are payed. Also journalists have facts and a blogger is basically what they know and opinion. Finally bloggers don't want to be considered journalists so, why call then something they don't want to be called.
A blogger is not a journalist, they are a blogger. I'm not saying this is a negative or positive thing, it just is what they are. There is no reason to mis classify them either way. Blogging and journalism are two different things and should be viewed as two different things.
Everyone has a blog now days. Some are of higher quality than others. Just because a person writes their thoughts on a topic in a public site, that does not make them journalists. There is a huge difference between good, high caliber writing and a diary. I have seen a lot of blogs that fall into the category of diaries, not journalism.
I do not believe all Bloggers should be considered journalists. A real journalist checks their sources and also has their articles checked for bias and false information. Furthermore, they relentless check the grammar and punctuation of their articles before publishing and often have people to check these things as well. Bloggers can post anything without checking the facts, without removing bias, and without editing. They should not all be considered journalists.
There's a huge spectrum of bloggers, and people on the opposite ends of the spectrum are very different in their legitimacy. There are very serious and reputable blogs on the internet, but, honestly, due to the size of the internet, the bad far outweigh the good in relation to the news.