I see no one has replied to your question.
The answer us that they are not.
It sounds unreasonable, but it is not. There are many very professional high time pilots who do not have an instrument rating and do not need one. Pipe line patrol, crop dusting, Flying in areas where there are no instrument approaches or traffic control, such as bush flying in Alaska, South America, fire fighting, etc.
And helicopter pilots who do do a lot of very weird stuff at low altitudes.
Thanks so much for the reply. My father was an instrument trained and qualified pilot. So I just assumed that was the foundation. Appreciate your comment and information. :D