Well, the "law" is more than what's written in statute; you have to merge that with case law. My understanding is that in Dowling v. United States, the Supreme Court specifically ruled that copyright infringement is not theft (specifically in reference to the section of US code that you link to, no less):
> Since the statutorily defined property rights of a copyright holder have a character distinct from the possessory interest of the owner of simple "goods, wares, [or] merchandise," interference with copyright does not easily equate with theft, conversion, or fraud. The infringer of a copyright does not assume physical control over the copyright nor wholly deprive its owner of its use. Infringement implicates a more complex set of property interests than does run-of-the-mill theft, conversion, or fraud.
https://www.law.cornell.edu/uscode/text/18/part-I/chapter-11...