So, is "escaping-adject-poverty-for-economic-benefit" then justified by Mexicans?
No. They are two completely separate concepts.
You are conflating a communist state where every citizen exists at the pleasure of the dictator with a country that is free but where economic opportunity is more difficult to find than it is here.
We granted Cubans the right to stay in the US if they made landfall here because they were escaping hell -- not a bad economy.