There are two ways to write short, topical blog posts. One is the brute force-approach, the other takes a slightly more indirect route.
The brute force approach endeavors to take readers from a state of doxa (which is to say, knowing nothing) to some particular conclusion. In order to accomplish this, the text has to provide the necessary steps to get from here to there. Mostly in the form of providing necessary background information, and some logical reasoning using this information in order to move things along.
A perfunctory writer can combine brute force with minimalism, and provide just the barest minimum required to propel self-directed readers to the desired destination. Introduce the subject, the prerequisite information, the logical steps and the conclusion - done. Those who want to understand can glean what they need from these words, and those who want to use it as a source that the thing in question is an actuality can use the fact that they are posted in a blog to great effect. Mission accomplished.
The more indirect approach does not aim to convey the bare facts of the matter, but also a specific point of view to go along with these facts. Some additional context to make the general into a particular, placing it firmly alongside other things that are obviously in the same category. You tell it like it is, as it were.
The largest difficulty in keeping this short is that the main objective can only be accomplished by the way, in passing. You do not accomplish it by merely stating a particular thing and dropping the mic; the very point is that you and you in particular is there to provide some verbiage on the matter, reminding readers about your point of view on these things. It takes a sustained effort, but is ever so effective once momentum has built up.
With enough momentum, the posts write themselves in their predictability, ever so perfunctory. -