There are two sides to every coin.
I don't understand powered boats running down a river, or a big lake, at speed in the dark when it's hard to see anything. While it's probably rare to come across and run over a kayak without lights, or a person floating because they capsized something, I wouldn't think it worth the risk.
Lights, horns, whistles are just common sense on non-powered boats, even in the daylight. There are simply too many people who buy a powered boat and never learn how to correctly, or considerately, navigate and operate the boat. Those people are dangerous to everyone. It's as irresponsible as a kayak without lights in the dark or not wearing your pfd.
Fewer bad things happen to those who consider, and prepare, for others lack of preparation and care. That goes for powered, and non-powered, boaters.