Is it possible that Thorpe have hit their ceiling in terms of potential visitors?
This, we live in a society where exponential growth is expected year on year from "the city" and when a company doesn't produce it, they get beaten up over it, it's completely immaterial that as the years ago on, the population is not increasing to take account of it.
Thorpe, much like Alton, cannot cope with the crowds it gets on a peak day now, and some bean counter somewhere wants them to magically increase gate attendance by 12% year on year (arbitrary figure pulled out my arse), it's never going to happen.
Anybody who is interested in coasters and lives within driving distance of Thorpe, probably already has an annual pass and there's only so much growth you can expect from a country whose population has been relatively static for the last decade and as others have said, tourists have no interest in visiting, they want "Royal", not Zombies (although any differences between the two may well be questionable at best).
Staff too, agree on that, never seen such unprofessional behavour from public facing staff as they have (and that's not even throwing an evil look at our favourite security team either).
I'm a big walking dead fan, will often watch it live on US time I'm that much of a fan, but it hasn't made me want to go to Thorpe any more than normal this year, they are five years too late with that franchise.