Were on earth are you getting this info? I looked hard to get a reliable info on the alloy for the Iphone 6... Could not find any and I doubt Apple is volunteering it (besides saying its series 6000). Did you, or anyone else, test it chemically or melt it?
I could not even find 6003 on Wikipedia amongst common alloys (pulled that number straight out from nowhere it seems!). The fact you used scrap aluminum as its definition, pushes the BS meter and button pushing way up there, as by definition scrap is mixed composition of unknown properties.
So, your telling Apple uses the worse version of series 6000, a version not even listed in the common alloys for 6000 for their phone!! Come on. Give me the references for this statement please.
Also, Apple says it uses an alloy specifically developed by them for the watch; everyone says it is a series 7000 alloy. Yet, you pull out 6061 out of thin air. When you read Apple's own properties for the alloy, it doesn't even match 6061 (6061 is the most common series 6000 alloy and wouldn't need Apple to develop anything, it is already in wide use). Are you calling Apple liars? Did you test an unreleased watch chemically, melt it, to determine content?