Great article and I totally agree with your point.
Here are some points that I quite strongly believe in:
-There is no such thing as a pure act of creation, everything we imagine always derives from a combination of elements we already know. Therefore there is always a certain degree of copying in anything we do. And as you mentioned very often it is unconscious. (what I do think is important as an effort is to try to feed inspiration less on existing design and more on other elements e.g. art, nature etc)
-Considering the principles of good design, there are just that many variations you can do on a logo while maintaining those principles… I am not saying that it is impossible nowadays to make an original logo, but by following the principles of a good logo in traditional terms, often the effort
of originality doesn’t pay off when compared to simplicity, recognisability etc
So even when you are not copying at all, the iteration of your logo sketches for example will probably end up being very similar to something that already exist cause it will follow the rules of good design.
-I think this is one of the reason why logos have really become a commodity nowadays, and why the consideration of a brand as a whole, in terms of extended visual style and beyond way beyond visual is now so fundamentally important, and the true differentiating factor.