it is interesting to know that Capacitor consumes and inductor supplies.
I have understood negetive power iR-jIXc is due to fact that it is consuming power,but
phase angle of voltage is lagging behind current by 90degree.ie(sqrt(r2+x2) and phase
angle is -90 degree.
So it is just about phase angle,not touching amplitude.
i think reactive power is negligible because of its complex nature .and it's all about a tendency but physically it may not have any applications.