I don't think they're too easy - just that grade boundaries need to be adjusted to that the proportions of A*, A, B, C etc grades remain roughly the same throughout the years.
I go to a well-achieving school, and me and many others feel that for some subjects (Maths in particular) it's too easy to obtain an A*, and the good and the really good candidates can't be differentiated - a shame for the most intelligent students.
Edit: Does A-level do this?