> I cannot stand the whole "culture fit" gambit. It's a job, not a country club. The idea that some people will "fit in" and others won't and that this can be determined during an interview is naive at best.
First, regarding the cultural fit: I think it's important that you share a similar mindset with the people who already work there. You'll get along better, and it is more productive. For example, if one person is much more assertive than another, and tends to get their way, we may miss out on the contributions of another. (A lot of very different examples here)
The second part: You're right, they can't give you a full personality quiz, but they're doing their best (oral communication and body language tell a lot more than having you fill in a quiz). They want to look for someone who fits in, so they bring you in and see if you do. What other way is there?
> ... best actors ...
I think if you intend to be an actor for the sake of a job, you're going to have a miserable time. Sure, I suppose this is the case if you value money more than satisfaction at you workplace. Which is where you'll make friends and spend a lot of your life, so I think you shouldn't, but that's subjective, so I concede this point.
> ... not fitting ...
This relates to the previous part in terms of priorities between just "getting the job" and "being happy with your job". As for the idea of not fitting in, I think it's too much of an exaggeration to think that people won't tolerate a few things here and there--but if you're entire view was different or fake to begin with, well maybe you didn't belong after all... you wouldn't be happy there anyway, so it's for the best.