Even granting every good intent in the world to authors and proponents of yes-means-yes laws, there is a fundamental problem, which is that these are unenforcable contracts, which are on their face, not valid.
Let us take yes-means-yes to a probably absurd end, and say that “yes” means a signed contract, drawn up by a lawyer, for certain acts upon a certain evening, between two adults (the undersigned), with no purpose of deception or evasion.
After that evening, contention arises about what was done and not done and why. In the first case, a party alleging that a particular contracted act was left undone will have no place to stand, as contracting in the positive for these sorts of things is not by and large legal. Well, this is not really the focus of yes-means-yes laws, so we will leave this aside. This leaves the other potential grounds for contention — a thing that did take place.
In the second case, a party alleging that a certain contracted act was done *but that it should not have been done despite the contract* will not be thrown out of court, but will be heard, and will probably prevail. Why? Because of the fluid nature of consent, which can, after all, be granted and withdrawn at any time, including monstrously enough — after the fact.
Let us examine attempting to enforce the contract in the second case. The contract says that a thing is to be done, and as the evening unfolds, that thing is indeed done — and in a way consistent with the usual sense of the terms in use at the time, and cultural expectations, and so forth. We are not talking about edge cases; we need not go that far in order to demonstrate the silliness of these laws. Consent is about the here-and-now, and cannot be contracted for at another time.
So we limit ourselves to consent given at the here-and-now, foregoing any lawyerly contributions such as written contracts, and signing, and witnesses. This is now *less* enforceable than the written version of such a contract, by any meaning of the term contract. So consent is by its nature a fleeting, difficult-to-judge thing. There can be no clarity sufficient to A) convince those who were not there at the event but who are motivated to argue the facts, nor B) establish beyond a shadow of a doubt for all time the validity of such consent even to those who were there, and even to those who partook of said behavior. That’s right — even he-said vs she-said is subsidiary to I-thought vs I-now-think, and for good reason. This topic is not amenable to legalistic treatment such as requiring written consent, requiring specified verbal consent, or any other attempt at formalization. It is a social thing buried in each of us, and some people will simply rail against reality.
I once received a remarkable piece of advice for men, which I will simply pass on without further comment.
“Always let her put it in. It will avoid complications later, and besides — she knows the way.”
Women also receive sage advice which serves them well.
“Don’t go in the bedroom unless you mean it. We all know what the bedroom is for.”
Sure, there are some who will find fault with these words of wisdom, and I don;t claim that these bits of advice are a cure-all. But they do a damned sight better service to those who heed them than do razing our cultural constructs and replacing them with a mirage of enforceable contracts hiding a tyranny of opinion and second-guessing.