The route is aiming purely at leisure traffic. Cornwall is actually quite popular with some Germans as it constantly features on prime time TV. Believe it or not, but (according to Wikipedia)...
[Rosamunde Pilcher's] books are especially popular in Germany due to the fact that the national TV station ZDF (Zweites Deutsches Fernsehen) has produced more than 70 of her stories for TV. These TV films are some of the most popular programmes on ZDF. Both Pilcher and ZDF programme director Dr. Claus Beling were awarded the British Tourism Award in 2002 for the positive effect the books and the TV versions had on tourism.
As your wife or mother will probably be able to explain, most of these books are linked to Cornwall.