That's anachronistic: the French Revolution (started July 1789) happened after the US Constitution was promulgated in March 1789, the Bill of Rights in September. The Reign of Terror was in 1792–94.
The real reason why the feared democracy was they were all rich men who feared taxation. Madison is crystal-clear:
> In England, at this day, if elections were open to all classes of people, the property of landed proprietors would be insecure. An agrarian law would soon take place. If these observations be just, our government ought to secure the permanent interests of the country against innovation. Landholders ought to have a share in the government, to support these invaluable interests, and to balance and check the other. They ought to be so constituted as to protect the minority of the opulent against the majority. The senate, therefore, ought to be this body; and to answer these purposes, they ought to have permanency and stability.