Why did night aircraft happen before all weather aircraft?

According to Wikipedia, "Pan Am was forced to declare bankruptcy on January 8, 1991. Delta Air Lines purchased the remaining profitable assets of Pan Am, including its remaining European routes and Frankfurt mini hub, the Shuttle operation, 45 jets, and the Pan Am Worldport at John F. Kennedy Airport, for $416 million. read more

Take off and landing was difficult at night, but it's much worse, regardless of light, if there's a high wind, torrential rain or thick fog. (FYI "All weather" is still something of a misnomer/ piece of wishful thinking - aircraft still get grounded due to weather conditions). read more

A night fighter (also known as all-weather fighter or all-weather interceptor for a period of time post-World War II) is a fighter aircraft adapted for use at night or in other times of bad visibility. read more