Why was each group of the french population growing increasingly unhappy during the 1780s?

The landed nobility grew increasingly unhappy with the amount of power that had been taken over by the royal throne over the years, reducing the authority of nobles in their own territories.  There also was tension between the older nobility of landowners and the newer "nobles of the robe," those who had been elevated to noble status by taking on positions for the royal government.

The bourgeoisie grew increasingly unhappy because they were afforded few political rights while paying much in taxes for the support of the nation.  They wanted a country that was better for business and enterprise, and for their voices to be counted in the political decisions of the country.

The city laborers and rural peasants were increasingly unhappy because they faced poverty and hunger, especially as bad harvests occurred in the late 1780s.  They also faced oppression by the superior classes and had duties imposed on them that those of higher rank could avoid.