Why would Aquarius be an air sign if it is the WATER bearer?

Aquarius is often mistaken for a water sign, due to its symbolism. Aquarius, however, has little to do with the realm of feeling which water signs deal with. Aquarius is part of the air triplicity (Gemini, Libra, Aquarius). These signs deal with the intellect, ideas, social relationships and communication. Those of the air triplicity manifest strong mental proclivities, with a tendency to rationalize everything. They generally see emotions as illogical and feel uncomfortable with matters related to them. Aquarius is a representative of fixed air. Fixed signs are stubborn and stable. The Aquarius manifests this in their adherence to their own (sometimes very strange) ideas and ideologies, as well as their persistent need for freedom.