History

I had a similar question so I looked up stuff about the Spanish and how it worked around Columbus (even though the concept predates him). In short, yes, they gained experience through a long history of infighting and conquering each other. The Spanish had some expeditions into Africa in the late 14th century which were quite profitable for them. They captures slaves and created sugar plantations on the Canary Islands. Plus there was all the stuff with the Reconquista which was the model for their colonialism. The same behaviors and policies from that period become the Encomienda System for colonies. The conquering of neighbors and forcing them to pay tribute had worked out really well for Spain. Encomienda did that but for colonies. The crown also made it legal for nobles to fund their own expeditions in return for a grant of the profits. If you squint really hard you can see capitalism taking shape.

Colonialism was fairly rational for the monarchy and investors. It had proven to make people very rich. For the monarchy, it was a cheap way to get huge returns. Columbus' first voyage only cost about 1% of the annual revenues for the Kingdom. The crown paid about 90% of the cost of the voyage, leaving the rest up to solo investors. Columbus debt financed the rest through Italian banks.

It's culmination of everything that came before, driven in the direction of chasing profits. Culturally, cruelty was a virtue and that helped justify the violence in pursuit of wealth.