A few days ago, Steve Brust said that with a few exceptions, he tried to keep his politics out of his writing. Elizabeth Bear told him that wasn't so; he wrote strong women, and that was political.
Which made me see a difference in people's definition of political. For Steve and Emma and me, a political act requires choice. We never sat down at the beginning of our careers and asked, "Should we write strong women or weak ones?" We wanted to write realistic women, which meant our female characters had to be as capable as the women we know. For us, writing strong women isn't a political act; it's an artistic one.
To be blunt, some writers don't write any characters convincingly, and some only write one sex well. If you have simplistic ideas about gender, your characters will reflect the limits of your ideas. If your audience shares your simplistic ideas, that won't hurt your career, of course—there are always people who want their facile ideas about men or women validated.
But if you want to write men and women well, you must always test your assumptions. A fine place to start is Cordelia Fine's Delusions of Gender.