Bingo!
Neelix who had many life experances was fasinated by the replicator and transporter the first time he saw/used him. Kes, who's never seen anything other than her underground world was never once in awe or curious about anything on the ship. She wasn't even surprised by a man popping out of thin air.(The EMH)
That doesn't make any sense.
Why ?
Perhaps the Ocampa have a rich literature that speculates about such aspects, and if anything, Kes spent several months as a servant to the Kazon (and was abused as well).
Also, if you were to suddenly be transported away to a starship by aliens that has a matter-energy converter and solid holograms, would you be popping your eyes out just because that society is more technologically advanced?
Kes was still thought to have been essentially a child back then (ok ... a teenager) ... and kids as such could be very open minded.
The Voyager environment would be new to her yes, but the Caretaker from her perspective was extremely powerful entity of which she knew.
Also we don't know the full background of the Ocampa race and what their culture is like.
Kes was a type of individual that was virtually speculating about aspects that her friends didn't want or dare contemplate on.
It's all a matter of individual perspective and open-mindedness.
Not everyone has to scream 'WOW' at a novelty or a far more sophisticated technology.