whether they want to display ads on parked domains, isn't it?
When I first noticed that I was getting a ton of worthless traffic, and paying several hundred bucks a week for it, I dug into the AdWords UI, and found only one option to disable, "Content Network". Soon after that, they added the ability to place ads on specific sites...but not the ability to say, "anything except spam sites, including Google's own spam domain hosting service". Of course, Google doesn't talk about their own spam domain hosting service much. But, it's clearly Google being evil. (Apparently most Googlers aren't even aware of this "service" from Google, so I guess it's kept quiet internally, as well.)
and then by "platform" .. Desktop vs iPhone + smart devices.
You can set content network to targeted though, but I don't see any way of totally opting out of parked pages. I agree with you, however, that this is not necessarily what advertisers want, although ultimately I think it could work out if Google maintains quality.