I think you're cherry picking. Plot surrounds Harry, Ron, and Hermoine and feature two of the three biggest villains in the whole series. So yeah.
I understand that, but I think you missed my point. This whole issue arose from payment of actors to appear in the ride. My comments were meant to convey that it is possible to create an attraction and a story for an attraction with minimal to no use of the main actors.
Yes the plot surrounds Harry, Ron and Hermoine. And yet only one of those actors actually returned for the ride. Universal was clever in utilizing smaller characters from the series in pushing the plot forward, regardless if they were the main focus of the actually story being told. Whether is was intentional or not, it most certainly saved money in paying the actors involved.
Again it could be just as easy then to point out other IP attractions in Universal that have minimal use of the main characters in the attractions story. MIB and The Mummy are perfect examples of that. Aside from Rip's narration, Will Smith only appears for a brief end of ride video. The same with Fraiser in The Mummy.
In the case of Star Trek, it is chalk full of iconic elements the could help drive a full attraction without the use of the main actors involved. They are the same iconic elements that have allowed the series to thrive for as long as it has regardless of the ever changing characters and cast.
An example: An attraction where you yourself are a fresh Starfleet graduate. An unknown distress beacon is picked up on an uninhabited planet, but to recent damage of the Enterprise (a great little inside joke about how often it is destroyed at that) you are sent on an mission on a smaller Federation ship to investigate. Insert any Star Trek character to facilitate that story and a icon adversary (the Klingons, Borg, ect) and you have a completely recognizable Star Trek attraction with minimal use of the main actors involved.
I'd argue it's taking into account the current state of the Star Trek "fanbase", but to each their own.
Like I said before, I think you are underestimating the Star Trek fan base. Star Trek is a multibillion dollar franchise for CBS and Paramount for a reason. I feel like a lot of this stems from people constantly wanting to compare Star Trek to Star Wars. Star Trek is never going to be as popular as Star Wars. Merchandise is never going to be as big a seller as Star Wars merchandise... Or even Harry Potter merchandise. That doesn't mean Star Trek isn't very popular and its merchandise wouldn't sell well.