I don't understand what that has to do with anything. You're copying something someone else created, for the express purpose of generating income, without their permission.

Who said anything about generating income off of pirated work?

Theft does not imply the intention to pay, that's kinda the whole point.

The definition of theft according to MW: the felonious taking and removing of personal property with intent to deprive the rightful owner of it

If you do not deprive the original owner of the property (such as: copying), it is not definitionally theft. Legally speaking, it is considered copyright infringement.