This is a fairly known issue in elec. design. What is happening here is that the case is acting as a Faraday cage (http://en.wikipedia.org/wiki/Faraday_cage) that blocks out signals.
It is not just enough to wear the designer hat. An engineer hat is absolutely essential as well.
It pretty well blows my mind that they just wrapped the whole antenna in metal and didn't think that it might cause problems. You shouldn't need to wear any hats at all for that one, just apply some common sense.
When I saw the thing, I assumed they must have come up with some extremely clever way to avoid signal attenuation. Turns out they were just ignoring the blindingly obvious. Oops.
> they must have come up with some extremely clever way to avoid signal attenuation
Which itself would be fairly incredible, considering that Steve Jobs and Jony Ive wanted to make the iPhone out of metal, and for three years they couldn't do so because of the antenna issue, and finally after spending what must have been many millions of dollars and many engineering man-years they came up with a sophisticated solution that was pretty good but even so still had widely publicized issues when it first came on the market.
It is not just enough to wear the designer hat. An engineer hat is absolutely essential as well.