I own the phone. If you cover the black strip in the left corner, you will slowly lose signal. It's honestly nothing to get worked up over; however, I can see how it would be a problem for left-handed people. The people who won't stop whining about it should either get a case or return the phone.
It is surprising they didn't figure this out in testing other than the fact that in field testing the phone was always in a case to hide it from others. Maybe that's why they are currently hiring three antenna engineers, some people were likely fired.