Is Harpsichord more difficult to play and learn compared to Piano?

Can a pianist play the harpsichord well just like a violinist playing the cello ?

Just wondering if perhaps harpsichord is harder than piano, in terms of dynamics, control of articulation.I was just looking through the Piano exam syllabus and the Bach Italian Concerto was in the Grade 8 exam syllabus for Piano, whereas the same Bach Italian Concerto is in the Syllabus for Harpsichord Diploma Exams. The same goes with the French Suites.

Anyone knows why is this?