Maybe its because I've got a premium pass but I do agree theres been a tonne of overreaction to all of this.
When you purchase a Standard Merlin Pass its clear in the terms and conditions that your not granted access to special events at Thorpe Park - Whilst its true the charge isn't in place at towers, you could say the same for Fright Nights (and id much rather a 1 of charge for the event than thorpe charging per maze)
Merlin / Thorpe have to ensure theres value to buying a premium pass, if you want entry into these events pay the extra and buy a premium.