^ Agree with this. In my personal experience of talking to people that's what has happened.
The subject of TP was brought up at work a couple of weeks ago, and the general consensus was "yeah I went there once. It was expensive and we queued 2 hours for Stealth." (along those lines.) There was a lot of negativity about queues and expense... THAT is the main thing many people are remembering about their trips to Thorpe.
I think they've just gained themselves a bad reputation tbh, and need to build it back up. People just don't have the money to blow away on things like Thorpe Park at the moment, it's as simple as that. Everyone's after better value for money right now.
Blaming the Swarm's marketing for their drop in attendance is ridiculous. The real reason people are not flooding through the gates is because people don't feel that it's worth it, especially at the moment when their target customers have literally no money to spare.