Sure, all of this happens. In the context of the OP, however, we are talking about a language that tends not to come with perks. This is the slang and patterns of those who have been excluded. Though, of course, it can be cool, in many circles to know their slang.It is understandable to a relatively small group. This can be good or bad, depending on whether you are in or outside of the group.
If you want to be part of that group, but don't speak their language, you won't get in. So naturally, you feel frustrated.
Also, if that group poses some kind of threat to you, and you don't speak their language, that renders you more or less helpless.
If you are part of the group, speaking its language helps you to fit in, despite whatever other differences there may be, and it makes you feel safe.
If you are not part of the group, but somehow speak their language anyway, that gives you some safety as well, because you have some idea of what is going on in relation to the group.
To put this another way Gedanken is not complaining - in the examples - about business language and slang. Much of which is less artistically put together and also masquerades as formal and even becomes formal language in ways black street/rap slang does not.
There we have a near dialect filled with slang that actually is part of a culture that actively excludes people, including the shapers of the the language G is complaining about. Knowing their words can help getting a jog and keeping and getting promotions/thriving. And the utterance of single sentence, like the one G quotes in the OP, would be enough to, for all practical purposes, end an applicants job interview.
It depends on the context for me. Two people can speak Spanish in a Walmart - the original scenario - and I may feel excluded, but I don't consider them rude.Other than that, there is the issue of simply feeling excluded from other people's intimacy. Just as we feel it is rude to whisper in other people's presence, it is rude for a few to speak in a language that only they understand, while in the presence of others. "Inside jokes" are also uncomfortable if you're not inside.
I have this wish and counterwishes.Moreover, generally, people have a tendency to wish that the world would be so as they wish it would be. Whether this means that everyone be Catholic, or everyone be vegetarian, or everyone speak a particular language or its variant.
To me the dissertation is more of a hzing ritual. It certainly can demonstrate certain kinds of thinking and the organization of that. But I think it is odd that it is one of the two gauntlets one must run, generally. That and oral interrogations.Completing a dissertation means that the student has some practical ability to produce a certain kind of discourse; and producing that kind of discourse is part of the education program.
We could of course wonder why go to college, or why college requirements are what they are ...