Why did German submarines begin sinking unarmed and unresisting merchant and passenger ships without warning?

Because the soon to be sunk merchant ship was radioing the subs position to the allies the whole time the sub was standing by awaiting for the ship to get it's passengers safely off. The sub was spending TOO MUCH TIME on the surface exposed to enemy hunter killer teams. German subs were being sunk and experienced skippers (captains) and their men were being killed because they were "being kind" (also known as "too nice"). If "ships to be sunk" did not radio off the sub's position, and if enemy hunter killer teams didn't destroy so many German Subs/Skippers/and crewmen; then the "Restricted" warfare would have cost the Germans nothing, and they would have and could have...continued.