This is not intended as a snob comment, but what Hermes understands (along with Bond St Association) is the whole area needs protecting - I
don't think it helped other luxury purveyors in Mayfair having Victoria Secrets or Abercrombie despite the dollar power of the brands (at the time) or bringing their target market.
I know people also think it must be a good thing, and maybe it is at LV or
Gucci, but I really don't think Hermes likes have queues round the block just to get in the store either.