I've always thought that nuns wear their habits on their souls.  Most Roman Catholics (or former Roman Catholics) can spot a nun a mile away.  Whether or not they wear a habit is no one's business but their own, as they decide within their own order (within any given order some may wear a habit and some may not).

The only ones who care are "civilians" who seem to feel that it is necessary for them to pass judgement on everyone else's business.