Apparently, his writing style was learned in his first years as a professor as a result of much pracitce.  In "Mills at Maryland," William Form had this to say about Mills' acquisition of the craft:  "Yet [Carl S.] Joslyn [Mills' department chair at Maryland]  importantly influenced Mills.  Mills wrote a paper that he circulated prior to the faculty seminar.  When we discussed it, Joslyn raised several points for clarification.  Mills was mystified by the questions because he thought he had made his points clearly.  When Mills asked Joslyn why he did not uderstand the text, Joslyn replied that Mills's writing was awkward, unclear, needlessly abstract, and difficult to follow.  Somewhat shaken, Mills quickly recovered and unabashedly said, 'I want to become a good writer.  I almost have an orgasm when I read a beautiful sentence.  Teach me to write.'  Joslyn agreed, but thought Mills didn't really mean it.  However, Mills persisted and Joslyn tore into the manuscripts.  Mills's writing quickly improved.  The contrast in writing style between his pre-1943 articles and dissertation and later pieces is striking."

Form, William.  1995.  "Mills at Maryland."  American Sociologist, Fall 95, Vol. 26 Issue 3, p40, 28p, 2bw