I have not been to blackpool, but from what i have read big dipper and grand national are both herratige england listed meaning they have to stay opperational in the same/similar form as currently so they will have to outlive everything due to the law,
seeing the centiment online, I think part of the problem is a lack of awarness of the rides & park from the public, only a couple people i know (not coaster enthusiasts) have heard of bpb but most have heard of alton and thorpe and bpb is about the same driving time from alton to me. I think this is some what made worse due to the push for online prebooked ticket sales, in a town where tourism is quite high and there are many alternaive attractions charging £50 per person on the day dosen't incentivise the impulsive purchases of holiday makers, for instace if it was a cloudy day they may not want to go on the beach, but there is a theme park right next to the beach that could be done.