Because like you, not everyone is sure they'll like the configuration since they haven't tried it. Most of them are priced in that "sweet spot", that includes many other potential boats to choose from with cabins, bathrooms, and other "extra" stuff that people may want or think they need.
They are a unique boat, and not a boat that can be included in a "list" of other various vee bottoms. You have to WANT a Gladiator specifically, just like you have to WANT a Cat. They are meant to give a sports car feeling, instead of a supercharged SUV feel like most other vee's.
All of these factors narrow down the kind of buyer needed for this style of boat.