A) the astronauts were professionals, not morons with a Kodak box camera.
B) The Hasselblad cameras they used were very very good
C) Many journalists and photographers and war correspondents in the 'old days' took a lot of photos without viewfinders - people weren't locked into screens like they are now.
D) The photos were taken in rapid series with motor drives - the chances of 'outstanding ones' goes up dramatically, which is why pro photographers use them all the time.
E) Come down to the parks along the Intercoastal in Cocoa Beach and talk to a lot of the old engineers that were THERE when it happened and still come out anytime there's a launch; they're glad to talk about their experiences and laugh at the nutballs who believe they didn't exist.