But would it bad to if only the good happens? What's wrong with a bit of optimism?
Anyway, to address your question:
Because then the British were a small minority, exhausted by WW2 attempting to oppress a large majority who clearly had natural justice on their side.
This time it is a large majority attempting to victimise a smaller minority for a reason which historically has led to wars, genocides and mass killing.
The effects of this gimmick was the obliteration of the small sector economy throughout the country and is now the backbone of financial crunch the country is facing. Also it completely failed to nail the black money problem it was proposed to solve. Widespread corruption and the BJP candidates themselves made sure that their rich friends cleaned up the money (I got all kinds of acquaintances who did).
We do not live just in the present. My optimism with the current government has eroded by their actions in the past. When such laws alienate an entire community of people by their religion (or skin color or economic status) and we are talking about holding them in detention camps, do we keep calm and let the atrocities begin to unfold or do we protest?