It's Star Wars. Sure, it looked silly and nonsensical but I don't go to Star Wars movies to validate my scientific view of the universe. The Veridian sun in Generations shouldn't have gone dark the very instant Dr. Soran's trilithium probe detonated but it did.
Frankly, I wouldn't even have used another moon-sized superweapon in this film and gone for something more along the lines of a bacteriological warfare plot against the New Republic to wipe out entire planetary populations, but I doubt that would have gone over too well with Lucasfilm in an era of real-life terror plots and doomsday scenarios. Creepier. More realistic and it wouldn't have involved violations of basic scientific rules to execute such a plot, but probably a non-starter in this day and age.