The Hidden Countries have lived in a set way of life since centuries ago with the rise of the Rikudou Sennin. Warriors who mastered the art of chakra use protected their nations valiantly, keeping their civilians safe and their government stable.
But when technology advances, so do the people of the nation. With technology, civilians gain power and the soldiers lose it. When the people can defend themselves, what place do the fighters have?
The Land of Snow has no real shinobi force. Their police ride horses and wear armor. They carry crossbows and swords and have little to no chakra use. Their villages are supported by trade and tourism.
But it's the Land of Snow that has immense ships ferrying people from the islands to the mainland. These ships are hulking masses of steel and iron, powered by huge steam engines and sophisticated steering systems.
So why do the Hidden Villages have such a lack of technology?
They have the tiny reconnaissance and communication radios. They have refrigerators for storing food over long missions, and electric lighting for late night studying and mission planning. They have breathing equipment for extended stays underwater, and electricity powered heating and cooling systems.
So why do they have such a lack of transportation? They have no large machinery to parallel the huge boats of the civilian countries.
Why is that?
A country is based on its infrastructure, and communications and transportation are a sizeable chunk of infrastructure.
If transportation is improved, won't the country improve as well?
And if quicker transportation is developed, shinobi will have more time to spend on tasks more important than escorting civilians from point A to point B, will they not?
And that is the greatest double-edged sword.
Improvement will aid a shinobi's time to focus on important missions, but if technology continues to improve, the way of the shinobi will soon become obsolete.
When security systems improve, what need is there for fallible human defense?
When weaponry improves, how can any human hope to stand up against it?
When society moves on, what place do the warriors have?
The warriors have no place.
So scientists and technicians quietly disappear as shinobi leaders have a slight increase in paperwork and society stays paused in its development.
Two steps forward, two steps back, and the warriors keep their place.