Let me stress that Gourcuff is a top player, there is no doubt about that. But the way some here harp on about him as if he is some sort of messiah is what makes me think he's overrated here.
Dabo has stagnated a lot and hasn't developed as well as he should, granted he is a solid fullback he hasn't really developed as well as he should like i said before.
That being said, the guy has been played out of position for two years now at St Etienne, he is being played as a leftback, a position which he obviously is not comfortable playing. But due to their financial problems and subsequently a lack of personnel, the manager is forced to play him there. I don't know maybe if he is played in his favored position he might as well reach his potential, but its a risk as he hasn't played regularly in his natural position for two years now.