"Wow, that's horrible. I didn't know that sampling and mashups required an explicit license."
The conclusion essentially boils down to "remixing is not fair use". Today's hip-hop is a direct result of that decision because sampling became prohibitively expensive.
It’s not legally fair use but no musicians consider it stealing.
Remember, the session players who wrote those hooks and grooves were not given a copyright. They got paid a flat fee. They could not care less if their drum beat, bass line or horn part was reused in a creative new way. The lawyers of the copyright holders sure do care, though!
"Copyright infringement is not stealing, full stop. It is just that, an infringement on a commercial interest that the government grants."
This perspective is incredibly obtuse. You use the law (that you fundamentally reject) as a justification for a semantic debate that no one is having.
Whether you label it as infringement or theft, the impacts are identical. Regardless of the terminology, you are withholding a payment that is owed for something you've unlawfully taken.
Check your footing, your moral high ground is located in the Mariana Trench, alongside debtors and fraudsters.
Looks like it's in the EU as well.
edit: Hm, Pelham v Hütter C-476/17 might offer some grace for mashups under the quotation exemption at least. Though I wouldn't rely on that.