They pretty much had all they needed
resource-wise in the country, trade was
not a prerogative and even though
Zheng He did go out exploring they
were not interested in colonies or
mercantilism
Mercantilism was pretty much frowned
upon within the Confucian system,
merchants did not produce goods they
moved them around and made money
which made them a drain on the
system. The few who were enterprising
and maybe came up with some new
product might often find themselves in
competition from the government
The Emperor system considered itself
the center of the world, the focus of the
heavens. When outsiders came they
gave tribute and fealty to the Emperor,
so the outside world came to them,
they did not need to go out