The problem is that with routes like Jersey and Dublin the airlines the airport needs to engage with and attract already operate to Bristol and in their minds see Wales covered already or due to the downturn see passengers from Wales as a way of making their flights at Bristol more viable.
With Edinburgh i wouldn't be surprised if airline's like loganair and Eastern may want incentives that Cardiff either isn't willing to give or can't. In the long run Wizz might be the better option for these routes.