Why could not the poor in Spain build up any wealth of their own ?

- Lack of resources

- Lack of opportunity

Explanation:

In order to accumulate wealth, people need to put up an investment first.

For example if you want to open a business, you need initial investment to purchase materials, hire workers, rent a building, etc.  Same thing apply if you want to apply to a high paying job. If you want to be a doctor, you need to put some investment in college tuition, expensive text books, etc.

There are some exception when the poor can obtain an investment through loans or pay tuition through scholarships. But the majority of Poor people In Spain did not possess these things. So they were stucked in their current condition and it's very difficult for them to build any wealth without help.