I think you'll have to be more specific as to what you mean with bad because his role in the French revolution was really controversial, especially according to the différent intellectual (and political) traditions. Hardliners would for example point his willigness to defend the King's interest (possibly helping and surely trying to cover his flight at Varennes), he's the responsable of the Champ de Mars massacre, was constantly accused by some factions of timidity, military incompetence or acting for his personal gain.

The problem here is both the fact that "doing something bad" is a very inprecise notion today, and even harder to apply to past events, especially one marked by constant and quick changes in attitudes, social normes and institutions such as the French revolution. And moreover, this period is also characterised by modern projections onto it. Different historical (and broadly, intellectual) have conflicting analysis on key events and persons. On the top of it, modern historiography is still evolving today, both in the way of looking into events and the analytical grids.

If you can read French, Nouvelle histoire de la Révolution Française by Jean-Clément Martin (former head of the French revolution chair at the Sorbonne) is a really good introductory book, providing a solid bibliography and outlooks on the major changes in historiography.