It is a profession of its own to create comfortably readable posts. The trick is to create a hierarchical structure in which information is ordered/grouped in subsections that make sense somehow. The most common mistakes (not only on this site, but in text in general) are:
Making too many sub levels without a binding header
Drawing attention to relatively unimportant details, making it compete with the comprehensive concept of the post.
Alltogether
That is why I REALLY find all those posts with randomly bolded text quite awfull. And like you I am pretty surprised those edits are approved many times.
