Just playing Devil's advocate here - I agree with your sentiment - but don't the vast majority of professional editors work with proxy media anyway and the full res stuff is only linked right at the end?The thing I really don't get is how Apple is trying to pose the iPad Pro as a monster 4K video editing machine, yet there's no way to actually get 4K content on it. WiFi isn't fast enough to move Raw DV 4K content over.
The iPad Pro needs something akin to Thunderbolt to be used for video editing in the way Apple wants to imply it can be.
Disclaimer: My wife has an iPad Pro for artwork and we both love it. I just can't imagine anyone editing 4K video on it. It'd be a huge pain just to get the video on it, not to mention storage.
Would be a nightmare editing a large project with full 4K media, doubt it'd be a pleasant experience on a Mac Pro never mind an iPad Pro.