How many made their wealth from rent-seeking and exploitation of the land rather than commerce?
Seems to me that most made their wealth in telcoms, tequila, beer, supermarkets, media, retail, etc.
Lots of people think they are poor because an international cabal of Jews steal their money, doesn't make them right. In SE Asia, you can replace Jews with ethnic Chinese to the same effect.
Go anywhere in the developing world and you will see plenty of areas where people own their own land and are still dirt poor as subsistence farming is not exactly a lucrative profession. In any of these places, many people move to the cities to find work.
I live in the 'developing world' and there is certainly a lot of corruption, cronyism, exploitation, and inequality before the law. Even if there wasn't though, there would still be a lot of poverty and migration from rural areas to cities.
If there is a rich(er) place next to a poor(er) place without fail the former attracts many people from the latter (especially if the latter has rampant violence and lawlessness due to the drug trade).
They are overwhelmingly economic migrants, not people fleeing racist persecution, and wealth inequality is not as simple as saying 'because racism innit'.