The gun industry in that era was full of make it now wait for the lawsuit later and kel tec being the way smaller company most likely did not have the resources to sue ruger and stay afloat or did not care. It was so big and popular at the time even S&W just released a glock with no license and went ok it will take like 5 years for this suit to be settled.
Discussion
you're assuming kel tec was trying to license, and nobody was biting
kel tec is not good at business, simple as that. maybe they don't care about selling in quantity because the business exists to support the design shop. but there's no way in hell they could not have found someone to license one of their designs for a fast cash infusion that would've let them expand their production facilities