It is purest sophistry to suggest that laws against theft exist to protect one against the consequences of his decision to put himself in a situation where theft from him would be possible. One might take every conceivable precaution against theft and still find himself a victim of theft. Even were everyone to be so prudent, laws against theft would still be necessary in order to dissuade potential thieves from deciding to take up the profession. Conversely, the revenge-porn law, insofar as it covers incidents in which the victim willingly took and sent the relevant pictures, protects people from their own choices, and is thus different in kind.
I really don't see what the benefit is
That one cannot conceive of a benefit for some kind of behavior is not grounds for making it illegal. Hence the argument that "no one needs an assault weapon" or "no one needs to buy liquor on Sunday" are in themselves insufficient to justify associated restrictions. Likewise, that one can conceive of benefits for a law is not grounds for enacting it. One must weigh as well the detriments, in this case the consequences of proclaiming women to be in need of protections generally reserved for those judged mentally incompetent.
If the law were to protect women from the posting of photos stolen from them, or taken without their consent, this would be another matter. As it stands, it should raise the hackles of feminists everywhere.