As I recall, Hollande decided to ignore all the advice around him[0]

>Mr Piketty’s second criticism touches on Mr Hollande’s tax policy. For years the French economist has argued for a more progressive tax system, which would merge both income tax, currently paid by only half of French households, and the “contribution sociale généralisée”, a non-progressive social charge paid by all. This too was one of Mr Hollande’s campaign promises. Yet the president has shelved any plans to overhaul the tax structure, preferring instead simply to increase taxes on the middle-classes and the rich.

[0]: https://www.economist.com/europe/2015/01/02/pikettys-snub