The word is dropped without explanation, in a place where you are expected to act. You have a second to decide whether to admit you do not know it. Most people do not ask.
That is the function. Not the side effect.
Pierre Bourdieu spent the 1960s surveying French households about music, furniture, food and photographs, and published the result in 1979. His argument was that taste is not innocent. What a person finds beautiful tracks how they were raised and schooled so closely that taste operates as a marker of class while feeling, from the inside, like a private preference. Knowing the right words is a form of inherited property.
Which means the door is usually not being guarded on purpose. It is being guarded by people who genuinely forgot there was a door.
The vocabulary is not the problem
The tempting conclusion is that specialised language should go. It should not. Precision is useful, and the terms mostly exist because a real difference exists and somebody needed to name it.
The problem is never the term. It is the term left standing, unexplained, at the exact moment a newcomer has to make a decision. A word explained in six words costs nothing. A word left standing costs a customer, and it costs them silently, because people who feel unqualified do not complain. They leave.
Where the waves came from
It is worth knowing how young most of this vocabulary is. The way coffee currently talks about itself is roughly twenty years old. The waves framing is generally attributed to Trish Rothgeb, writing in a roasters' newsletter in 2002, describing what she was seeing rather than issuing a hierarchy. It was an observation that hardened into a ladder, and a ladder implies that somebody is standing on a lower rung.
Twenty years. That is worth remembering whenever the vocabulary is presented as though it were ancient and settled.
Whose depth
By long-held account, coffee arrived in India around 1670, carried as seven seeds by a pilgrim called Baba Budan into the hills above what is now Chikmagalur. The hills still carry his name. That is three and a half centuries of people growing and drinking coffee here, largely without an imported framework to authorise it.
It is also worth holding onto because origin is easy to write badly. Atmosphere is always available: mist, weathered hands, heritage, a soundtrack. It is pleasant, it says almost nothing, and it usually turns up in place of the details that would have told you something. Pride does not need performing. It needs specifics.
Name the place. Name the person. Let that carry it.
The test we use
It is not a tone check, because tone is easy to fake and warmth is not the same as access. It is this: if a first-time buyer would have to ask somebody before they could act on something we wrote, it has already failed, however friendly it sounded.
Depth is not what needs protecting. Depth is fine, and most people want more of it than they are usually offered. What has to stay unguarded is the door.