Other way around. Western law has looked dimly for about the last 800 years on having property rights abridged.
If you steal my car, I don't have use of it. If I copy your book, we both have copies.
Further western law for the past 800 years looked dimly on the rights of women. Should we deny women the vote, just because that's how it's alway been done? Is an argument not required to explain why women shouldn't have the vote?
Anyone with common sense knows that copying my book is theft (Assuming standard copyright. I have released several books under permissive terms myself.) This goes way back to Dickens and Beethoven, Who were damaged by piracy, along with many of their contemporaries.
Was that done all the times copyright was retroactively increased?
>Anyone with common sense knows that copying my book is theft.
Just because we use the same language for ideas as we do for physical things. Doesn't mean they are equivalent. Calling it intellectual property doesn't magically make it property. And it is common sense that copying is theft.
Further book copying isn't theft, at least in the UK. Theft requires an intent to permanently deprive. If I copy your book I'm not permanently depriving you of it.
I don't necessarily agree with the GP, but I don't think you can reject the argument out of hand because you don't like the answer.
The GP has provided an argument as to why they are entitled to your copyrighted work. You haven't provided an argument in response.