Well, unfortunately it just didn't catch on. In many ways it made much more sense than the calendar system we still use today.

It also has the added benefit of celebrating an event most modern people probably can relate to and are in favour of (the bloody struggle and oppressive regime that came afterwards admittedly not so much though ...) instead of the arbitrarily fixed year of birth of a religious figure many people are more or less indifferent about.

On a side note, PHP interestingly has had native support for the Revolutionary Calendar for a long time: http://php.net/manual/en/function.jdtofrench.php