I believe that's because they usually avoid to speak of the political ideas. When they do -- in biographies, for example -- they generally can't avoid to bash David, firstly for painting Marat, secondly for being Robespierre's friend.

There is an ideological and political issue with all of this bashing that keeps on fascinating me. All the revisionists (French or Anglo-Americans) have a thing in common, they all seem to try to condemn the revolutionary idealism as if it were "absolute evil" and therefore needed to be destroyed.....