* Google’s API copying can’t be fair use if they weren’t copyrightable in the first place.
* If you do copy an API because of it’s beauty and not for either interoperability with software or interoperability with developers then it seems that you would run afoul of copyright.
That's why I said it partly moots the issue, not completely. Yes, you could conceivably still run afoul of copyright in some cases, but at first blush, this seems like a precedent that will make it very unlikely that that would happen. I guess time will tell, but that's my initial perception. IANAL, of course.
So don't do that?
Why would you copy an API save to be inoperable?
If it's just to duplicate someone else's design, I think I'm okay with that potentially being a copyright violation.
What downside am I missing?
"We shall assume, but purely for argument’s sake, that the entire Sun Java API falls within the definition of that which can be copy-righted. We shall ask instead whether Google’s use of part of that API was a “fair use.” Unlike the Federal Circuit, we conclude that it was"