The Taiwanese concept of "unification" is not what you're thinking of.
The Taiwanese faction supporting unification (usually the KMT) does not envision a world where Taiwan is/becomes a province of the PRC, they envision a world where the ROC governs all current PRC provinces, that is where they are in the seat of power in Beijing. I.e. this is something going in the opposite direction.
The opposing faction rejects these ambitions and wants Taiwan to go its own way.
EDIT: Since it's not necessarily military intervention.
The Taiwanese faction supporting unification (usually the KMT) does not envision a world where Taiwan is/becomes a province of the PRC, they envision a world where the ROC governs all current PRC provinces, that is where they are in the seat of power in Beijing. I.e. this is something going in the opposite direction.
The opposing faction rejects these ambitions and wants Taiwan to go its own way.
EDIT: Since it's not necessarily military intervention.