As a skier with a keen interest in the area, Chambery has only one advantage, it's half an hour closer to the Tarentaise resorts than GNB and an hour or so less than GVA. Attractive to the tour ops who provide buses for their punters but the lack of public transport is a pain for the DIYers. Other than that it is an overcrowded shed with limited facilities on Saturdays. And most skiers know that when it goes wrong it goes wrong big time, normally a couple of times a season.
I spend a lot of time (As far as an ex FJ Nav can) explaining the issues of a 40 day a year airport and the unique operational challenges of the terrain and that a better ILS would not help.
Generally, I find most people skiers would rather avoid it. Putting all the investment into GNB, with a bigger terminal and apron, would get my vote. But with CMF and GNB being in different departements that's unlikely to happen. Hence, my suspicion that the incentives at CMF must be very good....