Exactly how do people propose to theme a drop tower? As far as I can tell Detonator's themeing is as good as it gets for a drop tower. The only thing they could improve are the seats, but this is such a minor adjustment that I really don't see it happening; it wouldn't really make the ride any better, would it?
The themeing on Detonator is sufficient enough. The carriage is meant to look like a crate of TNT (suits me; fits the area), and the ride base is surrounded by more explosive crates, shrubbery similar to Inferno's, cannons (obviously the themeing looked more suited to the area with Pirates 4D opposite, as I always thought Calypso Quay was an amalgam of volcano-based island under pirate attack); the cannons have - and I've always considered this one of Thorpe's cleverer themeing ideas - fired at the surrounding buildings and left impact marks, so what more do you want?