The Brasilians created an industry from a strong subsidised home base. The first aircraft made were licenced built Piper models which were 'evolved' into the Bandit etc which was ordered in large numbers by Brasian Air Force etc to meet their domestic demands given that private type GA did not really exist there. The government then, of course, subsidised the following models. Bit a a small version of Airbus in South America.
Agree that government will is important.
I did not say it could not be done but rather aircraft must be designed and built that have a real customer demand. The Nomad eg did not...