Why inverse active mode of transistor is not useful?

Bipolar junction transistor internal design is in such a way that it will have high gain in normal active mode. Also when you interchange the roles of emitter and collector with emitter base junction reverse biased then break down voltage decreases as break down voltage is inversely proportional to the amount of doping. As emitter is highly doped compared to collector it is advantageous to reverse bias collector base junction in order to have the advantage of high breakdown voltages.