In ('modern') Britain the most sustained period of growth we've had was in the immediate post-war period where there was a high level of state intervention (eg. Establishment of the NHS) and very high taxes on the rich. Which is pretty much the bottom line on Hollande's policy.
Something's got to happen, and right now considering how badly 'austerity' is fairing across the world, investment and economic stimulus seems a reasonable idea, even if in the short term it worsens the problems.