We have previously noted that one consequence of forbidding marriage to clergy is that one gets a higher ratio of homosexual clergyman (link to brief discussion). Another consequence is that priests do to nuns the kinds of things that Maria Monk reported (link to Vatican's acknowledgment that this happens). The report makes Steve Hays' satire (link) seem not so far from the mark.
These abuses take place in part because of Rome's unscriptural policy of mandatory clerical celibacy, as Roman Catholic priest and former theologian, Hans Küng, agrees (link). Such a policy is a serious error and is contrary to Scripture, though we acknowledge that it is not an error as to an essential doctrine. If this were the worst error that Rome has, she would still be a true church.
There are, however, many other and worse errors in Rome's teaching. While Rome's gospel that involves subjection to the Roman Pontiff and veneration of Mary may not injure the bodies of its nuns, it is something that does far more serious damage - it harms their souls. The way of salvation is through trust in Christ alone for salvation.
(Update: Cardinal Schönborn appears to agree with Hans Küng and this blog)