Sadly this is the case. The same thing applies to the NRM in York to some
extent and certainly to the excellent Tim Hunkin "How television works"
displays at the Bradford Museum of Photography, Film and Television.

That'll be the National Media Museum- they've embraced the 21st
century and added the internet to their remit, but also included radio
as a counterbalance. My guess (at least for the Science Museum and
its outposts) would be that their exhibits nowadays are arranged on
the basis that they have to assume more or less total ignorance on the
part of the visitor. Similarly, the LT museum probably operates on
the basis that they have to have a Routemaster because people expect
to see one, with no real understanding of the context or of the old
London Transport as an organisation which set itself out to sponsor
advances in British design and engineering. It's a pity they don't
have space to do something like the Glasgow transport museum and have
a mock-up Underground station at least- perhaps Acton needs to be
built up to be the enthusiasts' centre with Covent Garden as the
general interest base for tourists.