Oh dear, where to start with this...
> It's a job, not a country club.
Yes, it's a job, but your ability to deliver on your work is not defined merely by private metrics like how fast you type, how many lines of code you can write a day, or even how knowledgeable and experienced you are about C++. Pretty much every job that you might apply to involves very large amounts of communication with your colleagues. When that communication breaks down (which it does even when you are a good culture fit), all sorts of elements come into play to help get things back on track. Also, when there is a need for rapid change (which there is on an almost daily basis in any company that's not on a straight path to the cemetery), communication and how well you gel with the rest of your team becomes the critical factor for how fast that change can happen.
"It's a job, not a computer game," I would reply. You can play your game by yourself with no interactions. Jobs require mature people who know how to communicate and behave in the target environment.
> What you get are a bunch of new hires who's only qualification over the not-hired is that they put on a good show for the interviewers. I'd say they are the best actors, but that doesn't cover those very good actors who make the mistake of playing the wrong part. Say you are willing to work through weekends to meet deadlines ... oops sorry, you guessed wrong. In this office that attitude is too competitive. We are going with those who guessed "no, weekends are for relaxing" and don't think you would get along with them.
If a company hires based on superficial answers like this, and thinks they're hiring based on culture fit, they're totally missing the point and they'll probably fail. Culture fit is at the same time far more subtle and far more concrete than this. Superficial features like whether you say that you're willing to work weekends or not are irrelevant. However, little and big details like how you walk down the street, whether you are open to someone questioning your ideas, whether you let someone else walk through the door first, whether you are a well rounded person with more to bring than just "I'm a great programmer", and, indeed, whether you recognise that you do want to work with people that you like and get along with, whether you you care about what kind of people you're going to be working with - individually those might be easy to fake, but as a whole, it's as hard to fake that general picture as it is to fake knowing about programming (to a programmer) when you're not a programmer. Even if you learn stuff by rote, details will slip.
> The message this sends to current employees is also evil: if you don't fit in perfectly we don't want you. So everyone shows up to work in costume, wearing a mask, because they fear standing apart. Bring the wrong suit or express the wrong opinion and you might not "fit" anymore. We often hear about a lack of visible diversity in IT. How can we expect to achieve visible diversity if we cannot yet tolerate emotional and cultural diversity?
That's the message, perhaps, if the company sending that message is totally stupid. Yes, culture fit matters, and yes, people can drift out of culture fit. But this is not something that happens suddenly, it happens over a long period. People don't suddenly come to work one day with a completely different outlook on how they want to behave at work. Obviously, if their definition of culture fit is based on childish, superficial details like whether you wear a suit, then yes, you'll get dumb behaviour from said companies.
My experience is that, quite unlike what you describe, organisations with culture fit enable people to stick out more. Because you know you're surrounded by relatively like-minded people, you tend to feel more comfortable being yourself. On the other hand, in an environment with a bland mix of employees with no consideration of culture fit, people tend to much more harshly punish people who stick out. Take a company like Zappos, which definitely cares about culture fit, and has as one of its explicit values "be weird", and compare the types of behaviours you see in that company to what you'd get somewhere like UBS or any typical traditional large corporate, which don't tend to care about culture fit, and you will easily see that people at Zappos tend to be much more willing to stick out - it's the ones working in the banks that have to wear masks all day.
> Employees and prospective employees should be judged on on their work product, not on their ability to emotionally camouflage themselves.
See above point - it's not about emotional camouflage, unless you're in a dumb company that doesn't understand the point of culture fit. It's about being emotionally intelligent and well matched to the people you'll be working with, so you feel comfortable being yourself around them, and don't have all this extra friction of working with people you don't really like or get along with.
> Did Office Space teach us nothing?
Yes, it taught us that the superficial understanding of culture you're describing can be implemented in horrible and somewhat comical (if you're not stuck in it) ways. It taught us that "pieces of flair" is a terrible way to measure enthusiasm, that "hawaiian shirt day" is ridiculous, that bland cultures generate zero loyalty or wellbeing, that culture, or lack thereof, can be a ruthlessly efficient demotivator.
In other words, it taught us that actual culture fit really does matter.