I think it's incredibly frustrating as an ending, when you first encounter it. You feel cheated, or I did. Then the idea develops that the cheating is part of the point.
On another subject, what do people think of the TV series removing the white supremacy aspect? For background, in the books, black people are sent to a different area of the US to farm. They never mention anyone who isn't black or white, so I was never sure what happened to people who were Asian, Hispanic etc: they let Jews stay if they wanted, but only if they converted. And in the essay at the end they allude to white birthrates in particular.Then obviously the series is quite explicitly multi-racial.
I had mixed feelings about it. The sort of people MA is basing this on are usually bound up with nativism, white power type movements. It's harder to root Gileadean ideology in movements that already exist, without it. The creators of the series said they didn't think, in a scenario where no babies were being born, that people could afford to be fussy about the ethnicity of the ones who were. I sort of get that, but equally in that case it's weird that there isn't explicit racism in the TV series (although I guess the ones in charge all seem to be Northern European). They're effectively saying that overt racism disappears in a theocracy!
I know also the show's creators said it would be problematic to do an all white series now, because the question would be, why are we focusing on the white people in Gilead instead of the black people that got shipped out to Nebraska or whatever it was. I get that, but personally I'd like to see and read about both stories!