So they started developing the Hyunmoo series. The Hyunmoo-3c has a range of 1500km, it is domestically built unlike the previous Hyunmoo missiles which were actually old Nike missiles from 1950s. It's interesting that South Korean engineers added a slot for carrying nuclear warheads (possibly had plans to develop nuclear weapons at some point in the 1970s).
Cruise missiles don't give the same power projection like a ballistic missile tipped with nuclear warhead. It can be intercepted which limits it's reach.
NK is predominantly rocket salvo and shell artillery. This may be basic tech, but its very effective militarily.
Cruise missiles are damn difficult to intercept. And for each plane with "bunker buster" dumb bombs, you can buy a salvo of very clever bunker-busting cruise missiles which don't have to bring their pilot home after.
