I do not see why it was bad the Red October was so silent.

this sub was quiet... too quiet

From the perspective of the Soviet navy, it was good that Red October was silent. By being silent, it was harder for the ships of other navies to detect it. That was the whole point.

The Red October was a missile submarine. As pointed out by the experts it could be off our shores and firing it's missiles before we even knew it was there. Good for the Russian Navy. Bad for us.