She never acted like a science-oriented person.
Are all science-oriented people supposed to behave the same? I find that statement strange.
Anyway Dax as scientist was used sometimes. Not really during the Dominion War or every episode she was in.
Some examples though
Emissary: Discovers the Bajoran wormhole.
Shadowplay: The whole village and people are holograms
Rivals: The laws of probability have changed!!!
Playing God: I discovered a universe.
The Quickening: Helping Bashir with the virus.
Rejoined: Helping with the artificial wormhole thing
Children of Time: Wants to investigate the planet.
A good list, and it's a solid, if simple, point that the Dominion War unfortunately placed Starfleet's continuing mission of scientific inquiry on the back burner while it fought to defend the Federation and its allies. As Dax's many lives left Jadzia with multiple skill sets to draw upon, it is only reasonable that other things she did well, such as piloting and commanding in Sisko's absence, came to the fore during that conflict. Regrettably, Jadzia did not survive, and while Ezri Dax likely had many of those scientific skills to draw on, her difficulties in adjustment and the demands of circumstance kept her from displaying them much in the episodes.