It's true that my experiences come from the physical sciences (med school and now grad school for biochemistry). But I have some experience outside that. One of my undergrad majors was political science and my wife is a professor of Spanish and linguistics. Polisci at Michigan seemed pretty serious, but maybe that was different in the direction you mean (somewhat more lax). Still, I think the difference would be easy to overstate. There's lots of ambition/competition in those halls and more to learn than is possible in a lifetime. For my wife, it's seldom acknowledged by outsiders, but linguistics is steeped in the scientific method, the functional anatomy of the mouth/throat, the nonstop evolution of languages, and neuroscience. It isn't usually regarded as a "hard science" but prob should be. And my wife will admit that she gets several students who enroll thinking they can blow it off. But, on day one of each semester, she has taken to introducing the necessary effort level as comparable to what they'd expect if this were physics. And it generally works. They get wide-eyed then they buy in or disenroll, which is good for everyone.
Spanish is probably the closest to what you've described. For many reasons, students are more likely to treat that laxly**. So stronger examples of your sense do exist. But I never meant to promise they were nonexistent. I just think the problem is focal not global, and generally under control.
**(Probably for many reasons. We live in America, where, unlike every other nation, a single language dominates from ocean to ocean, and because of our influence and economy, English is becoming a sort of lingua franca worldwide, so we don't strictly *need* to move beyond English to communicate with neighbors as they do in Europe, for example. Of course, that can change - the US has the 2nd largest Spanish speaking population in the world - but I digress. Americans also can sometimes have unhealthy attitudes about Spanish born of disrespect of the people who speak it. And these things, even if none of it is meant as mean-spirited, can make US undergrads more likely to blow off a language class with the false idea it'll be an easy A and that's especially true for Spanish.)