I often lead Botanical Society walks for the public. The Southern African Botanical Society old codgers (and that is 95% of members) deplore common names and exclusively use scientific names. It is almost a badge of membership. But the general public glaze over at the first mention of a scientific name, and by the third one they are no longer interested at all. At that point one has to quickly invent a few names on the fly and they all nod sagely and get really excited asking quite perceptive questions. Quite a few of these names stick, and surprizingly pop up in unexpected places like newspaper articles and commentaries for the area. The point is the public want names that can relate to, even if it did not exist 5 minutes ago. Our national flower has a dozen common names which all get used at different times by different groups. So what is wrong with that?
In Natal, where there is a strong English tradition, the botanical guides all know the English, Afrikaans, Zulu and Latin names for EVERY plant, and - where appropriate - additional names for different parts (e.g. where they are used medicinally) - and in the south the Xhosa name as well. Where these names came from is anyone's guess, but they are now part of the botanical culture. Who would have guessed that 250 years ago almost none of these plants had an English, Afrikaans or Scientific name. During this period someone invented all these names!
So what is wrong with carrying on and completing this task?
Every year thousands of Capetonians take to the streets on rainy evenings in August to help rescue the Western Leopard Toad during its mating migration. Almost none of them know the scientific name and dont care too hoots what it is:it is utterly irrelevant to the entire community.
Specific to fungi: our local ZA field guides have over 70% of entries with common names, the more recent guide including several names within a language for some species. If editors and publishers know what sells a book and ask authors to invent them, then clearly they are serving a public need.
Expecting unique names though is a tough one. Whose name becomes correct, and which communities are wrong in using that name? Scientific names are for preventing confusion: vernaculars are for daily communication. Locally common names do tend to be unique, but between regions or groups this is not true. There are legal issues: such as when a product is unavailable and another with the same common name is substituted. In the old days all doctors did a full degree in botany as well - today they dont even need Latin to practice medicine and dispense drugs: most doctors today would use common names and not be able to tell you where salicylic acid came from.
Like it or leave it but he popularization of science is about vernacular names: how many birders today could tell you the Latin Names? - 50 years ago the lingua franca was the scientific name. Why should plants or fungi be any different?