Why didn't the Spanish colonists occupy Zhihu in North America?

Of course, the Spanish colonists wanted to occupy the whole of North America, but they couldn't.

First of all, there are not so many people in Spain to occupy it. The Spanish came to North America in the16th century. At that time, Spain had a population of only 8 million, which was not enough to farm locally. Why do you want to farm in America? There is no one at home. What if France calls?

Secondly, Spain is a southern European country, and Spaniards like warm sunshine. In most parts of North America, especially in the eastern plains, the winter climate is very cold, which the Spanish are not used to. There are no high-value resources in the eastern plains, and the Spanish will not be satisfied with farming.

The Mexican plateau has a cool summer climate and contains a large number of valuable gold and silver deposits. Because the number of Spaniards coming to America is very small, they can only concentrate on the precious metal mining in the American plateau, and pay little attention to the planting in the eastern great plains.

After all, you dig for gold and your neighbors farm. What can't you accept? If you don't accept it, there will be no place to buy food with gold. Is this really good?