One reason could be that consumers aren't technically owning anything, but merely being sold a license to use an application/movie/music for some random amount of time.
Here in the EU, the CJEU rejected the 'it's only a licence' argument and characterised software downloads (that aren't explicitly limited to a fixed length of time) as normal sales, in Oracle v Usedsoft -- in particular, they're sales for the purposes of the First Sale Doctrine. So I could buy your app, use it, then extract the apk and sell it on to someone else, and you couldn't sue me for copyright infringement (as long as I remove the apk from my own phone, of course). (IANAL).
I'm not familiar with US law but my impression is that, on the whole, most states' legal systems are a whole lot less consumer-friendly than the EU, so presumably the same is not true over there.
