If you can't put your finger on what's going on here, you need to first learn what an intransitive verb is. Then, that "blog" is such a verb (from the OS X dictionary, which I assume is based on common usage, seeing that it's such a new word). "Sleep" is another example of such a verb. You don't sleep the bed any more than you blog the post (or the cow). That's why we have the word "write".
Now, would you even say "How to write insightful" rather than "How to write insightful posts"? Because if you would, you actually want to be saying "How to write insightfully" - writing insightfully is the act of writing "insightful x", but dropping the x. You see, they already thought of that. Grammar acrobatics should be left to people who have a very strong command of the language - it will destroy your writing otherwise.