I believe that's the key insight. "Intellectual property" is good (in the sense of generating lots of work) for the legal profession. Judges tend to rule towards things that benefit the legal profession(s), and against things that don't benefit those profession(s).
However, you're wrong in point of fact. Copyright is an English law thing, a statute law, not a common law. Look up "Statute of Queen Anne". It's from 1710. Patents seem to be a British or Venetian thing. The USA almost didn't have a patent or copyright system, Thomas Jefferson was quite against them. For a long time, the USA allowed immigration on the basis of possessing some skill or patented idea - the USA was an "IP Outlaw". Not too surprisingly, this coincides with the USA's period of industrialization.
"Intellectual Property", the idea that one can own ideas, is just a bad idea, from an economic standpoint.
Copyright law was also largely invented by Britain dating back to when the printing press was invented in the 1600s.
Trademark law is even older dating as far back as the Roman Empire. The first modern Trademark system was actually set up by France.
Your assertion about this stuff being American inventions is wrong.
The UK made nothing to spread it, the US made sure it's more universaly accepted than the Human Rights convention.
The Berne Convention was developed at the instigation of Victor Hugo of the Association Littéraire et Artistique Internationale. Thus it was influenced by the French "right of the author" (droit d'auteur) (...) Before the Berne Convention, national copyright laws usually only applied for works created within each country. So for example a work published in United Kingdom by a British national would be covered by copyright there, but could be copied and sold by anyone in France. (...) The Berne Convention followed in the footsteps of the Paris Convention for the Protection of Industrial Property of 1883, which in the same way had created a framework for international integration of the other types of intellectual property: patents, trademarks and industrial designs.
Have you heard of the British Empire? The UK did quite a lot to spread their legal traditions.
Really.
Patents, Copyright and Trademarks are all American inventions that have spread everywhere in the world. Many Americans think it goes too far, but in the fraternity of lawyers and judges, IP rules.