The premise isn't entirely true. After Napoleon's second defeat, France lost a portion of Savoie, the city of Landau in Alsace, the city of Saarlouis, and a few towns in what is now Wallonia, Belgium. Outside of territorial losses, France was occupied (at her own expense), and had to pay large war reparations to the coalition.

Firstly, the coalition was created to combat the French threat, the threat of revolutionary ideas that the French republic posed and Napoleon himself and not the annexation of France.

Secondly, the annexation​ of France or the carving of French territory would create a terrible imbalance of powers and Europe and would not benefit all of the coalition members as they are too far from France.

This can be seen in the congress of Vienna where the delegates from the main powers of Europe, met to redraw Europe's boundaries with the aim at ensuring peace and stability in Europe by carefully balancing the powers in Europe, which they were successful in doing for nearly a hundred years.

Maybe this is a seperate question, but could anyone speak specifically to why France was allowed to retain the German cities/principalities it conquered on the West side of the Rhine? Weren't there some very angry exiled princes somewhere that wanted their territory back?