Personally, I think Blog is a form of expression in a desired way. It is a free way and will of expression that has no limitation of boundaries. You blog because you want to express and that's what make it beautiful. It's you and your voice with no minimum level of adulteration of any sort of fake expressions. It has no interpretation and meaning, it is your voice for the action and things happening around you. It is closely related to a distinct human behavior that is more subjective to resistance and survival.
As said we humans survived the evolution process because we could always fight and voice our will. I guess blogging is yet another adaptation of will and survival that has evolved in the most protagonist way in materializing the form of a skill.
Its a free will of connected words in creating a meaning.
I think its the inner side of your voices and experiences that comes out in available form of communication or social media or through your actions. Defining and contrasting it within a pattern or limitation is not a blog but a more precise form of tactile writing.
To be very specific blogging may be an interest but for most of the people its a repercussion of interest that comes with a feeling of expression. It may be a series of expression but it has various sides of collaboration and condition which needs to be understood.
As per person and case, Blogging comes as an addiction to speak against action or against impunity or writing in terms of easing your thoughts and cognitive process. The visibility and clarity of what you see and think is something that completely affects your blog.
You can just release your frustration or anger with your words that are more effective to express in terms of human behavior.
I say "Blogging is a silent art of fighting that has more power and conviction to fight against impunity or for justice."