Here's the thing.
You know how hard it is to prove rape? Especially in cases of, eg, date rape, you know how hard it is to prove to any reasonable standard of evidence that whatever sex occurred wasn't consensual, especially in cases where the rape wasn't violent (eg if he wasn't rough, just didn't take no for an answer, and she was too scared to fight back)?
Well, it would be twice as hard to prove that not only was an accusation of rape truly false (barring cases where, eg, no sex occurred between the parties), but that it was intentionally and maliciously false, rather than being a matter of, eg, mistaken identity, or mental illness.
Also, as far as I'm aware, false accusations of any other crime--theft, say--are not prosecuted to anything even remotely like that degree.
But I would agree to something like this:
An intentionally false rape accusation that goes beyond making a false report to the police (that is, one where it actually goes to trial or whatever) would be a serious misdemeanor, worth up to a year in jail, depending in part on how far the accusation goes (eg whether or not the alleged rapist was convicted). Further, any such conviction can be used as evidence in the defendant's favor if the same alleged victim makes any further rape accusations.
But by intentionally false, I generally mean cases where either no sex of any kind occurred, or the sex that occurred was with someone else, that the alleged victim could not reasonably have mistaken for the alleged perpetrator. Or, at a very minimum, cases where the alleged perpetrator can pretty solidly prove that the sex was, indeed, entirely consensual (eg texts or chat logs both before and after the alleged rape indicating a positive response), rather than the alleged victim simply being unable to prove that it wasn't.
And, with a slightly lower standard of proof, those falsely accused of rape should be able to sue for damages, if they can reasonably prove that their accuser did so maliciously rather than out of genuine error.