Titus Brown wrote a blog post on why blog posts are better than scientific papers. Here are few more reasons for that.
Publishing blog posts is lightning fast(how fast can you type?). You can just publish it with a click after writing. However with scientific papers you have to wait months to get your work published.
Blog posts are easy to edit. If you are using a version controlled system like git, any one can easily collaborate. You can also leave comments on (most) blog posts and can have discussion with the author and/or others. Scientific papers once published are hard to change.
To publish blog posts, you can setup your own blog or use services like medium. There are no gatekeepers who says that you can't publish a blog post because they thinks its not worth it.
Blog posts tend to be casual and organic. You can crack a joke and readers will enjoy it. Scientific papers are formal. You spray some sarcasm and your paper never gets published.