From your link:
The French billionaires that promised to donate, such as businessman Francois Pinault, energy executive Patrick Pouyanne, and businessman Bernard Arnault, are witholding their donations because they want to see how the money will be spent.
Frankly, I would do the exact same thing as they are doing---not that I could be doing it!
Had they immediately paid up they would be without influence on how the money would be spent. If I were to give (which I can't) a billion euros to someone I damn sure want to know how it will be used.
"A pessimist sees the difficulty in every opportunity, an optimist sees the opportunity in every difficulty” ---Sir Winston Churchill
"Political extremism involves two prime ingredients: an excessively simple diagnosis of the world's ills, and a conviction that there are identifiable villains back of it all." ---John W. Gardner
“You can’t go back and change the beginning, but you can start where you are and change the ending.” ---C. S. Lewis