It's incredibly easy for developers to add hi-res artwork to their apps
I guess you've never worked with a graphic artist.
Mine has invented some new math, whereby elements in the image change size by a variable amount when doubling all of the dimensions.
The math is so new that even my designer doesn't understand it. "I don't know how it did that."
That's after the first go-around, where he sucked a Photoshop image into Adobe Illustrator (you can do that?) re-imported it to Photoshop with a different pixel resolution, and somehow expected it to look better. Of course, the original when zoomed 2X looked IDENTICAL to the new, "high resolution" image. Another hour blown doing something I could have done myself in The Gimp in 5 minutes. At least I would have only wasted 5 minutes.
The second go-around required hours more work, because he had done a transparent punch-out effect in Photoshop, because he hadn't been able to figure out how to do it with acceptable results in Illustrator. So, if I change a color or width somewhere, it requires hours more work to add back the punch-outs.
Oh, and then I had to pay for all this nonsense by the hour.
So, I guess you've never worked with a graphic artist...
On the other hand, I'm running a logo contest on 99designs.com, and so far I am delighted - with the results, the process, and the cooperation and good communication with designers. In the future, I have to say, the bulk of my graphic work will go to 99designs.