Nope, that is not DRM - as DRM is a system to limit the
usage of a given media. But let's not discuss words here.
I think it is pretty obvious that no one has a problem with that kind of download restriction (though I personally would prefer a user-registration with the ability to redownload a given media, but as I am a grown up, I can handle my own backups

)
But .. we all have a problem with normal DRM - that is a DRM that restricts your usage, the devices or the software you read that book on, or similar.