Sommeliers are professionalized, with courses & exams. But I don't believe they are actually judged on their ability to taste wines and detect flavours. Designing such tests would be simple - rate of successful flavour identification based on data from other Somemeliers.

Instead Sommelier exams are subjective - candidates are judged by another Sommelier on subjective criteria rather than objective measurement. In my opinion they judge it as a dramatic performance: how quickly can the candidate rattle-off various flavours? How "high class" is the language they use to describe the flavours? How does the candidate present themselves? Sommeliers dress in fine suits, but this should have no impact on actual wine tasting ability. Yet I am sure if I showed up in a draggy old t-shirt I would fail regardless.

The whole industry seems allergic to objective scientific measurement. I am sure Sommelier's do have some ability to identify varieties, but are they actually tasting all those subtle hints they list off? I doubt it.