I admit I don't watch French news closely enough that I would feel I was actually making an informed vote in their election, and I trust that you are probably much, much more familiar with the candidates than I am. But let me elaborate as to why I said that. The policies that Macron helped enact as Minister of the Economy, Industry and Digital Affairs aren't exactly the ones that are the source of Hollande's unpopularity. Meanwhile, Hamon comes across (at least to me) as an even more naïve version of Hollande only with some "but I can get it done!" thrown in. If a major selling point of your candidacy is that the current president from your own party has no idea what he's doing, you're kind of in a lose-lose situation. If you argue he does know what he's doing, despite his unpopularity, you're also in a lose-lose situation. That's what I meant by him being saddled.
Perhaps you could help dispel with fiction by pointing out what someone who disapproves of Hollande would find promising in Hamon's candidacy, apart from the fact that he resigned from his position.