Why some countries are wealthier than others?
One argument brought forward (it is a generalization/argument for lack of infrastructures) is the Acemoglu-Robinson hypothesis of extractive versus inclusive institutions.

Long-story short: some institutions are good for (long term) growth ("inclusive"), and some are good for short-term extraction of resources ("extractive"). Depending on whether the elites / rulers of a country (colony) had long-term plans of "staying in a country" or whether they wanted to just "quickly get everything they can" out of the country, they installed these different type of institutions.

See also their slides and book.