Prost,
Is not as bad a manager as he is recorded to be. There were a great many challenges that lead to the failure of Team ProstF1 and not all of them were a result of bad management.
Those challenges were Peugeot and the French Government, both of whom promised backing that was never delivered in full. Thereafter it was a matter of finding funds continuously. Also his hands were tied by whom he could recruit.
I think if Prost were to start up his team now, under budget restricted conditions he would be far more successful.
But ultimately he must take the rap for failure of the team. That does not make him a bad manager though.