if nobody on your planet has any privacy at all, that means they're all having sex, giving birth and using the john while elbow to elbow and shoulder to shoulder
Which is how humans in Europe did it for the past couple of thousand years, too.
Privacy in that sense is an extremely recent invention, basically a luxury afforded through conquest of more habitable and sheltered space by technological means.
the entire species is composed of complete morons
Well, they did make it explicit that they refuse to consider contraceptives because of abstract philosophical reasons, or "love of life". It's not something they can get over without ceasing to be.
They could just as well say we're complete morons for having to seek privacy for sex. That sort of self-imposed idiocy is life-hindering masochism at its worst, lacking rational basis.