If the OP had only written "Horns should come equipped with different sounds to better communicate with other drivers", which is the overarching gist of what they were musing, the thread would be different. But they added the story which prompted the thought. Instead of considering the benefits, or even drawbacks, of the proposed suggestion- you fixated on the story itself, seeing a great opportunity to interject some moralizing and also indirectly boast to the rest of the readers about what a good driver you think you are. There's nothing to debated about what you wrote, everything you said is correct.

But it's easy to admonish others opening up to explain a mistake by clubbing them with an imagined perfect scenario.

Should all people be better drivers? Yes, of course. Is that realistic? No. And is it really related to the actual proposal the OP opined on? Very tentatively.

Also, I certainly don't think you are a bad person. A very human person. Just like me. And all the upvoters who are now thinking "Yeah, OP's dad should be a better driver! And thinking that makes me feel better about myself" instead thinking about auditorial communication.