yes but it happens in any family reg- capitalism has many definitions, I would agree also Muhammad PBUH was capitalist as he kept property (and traded with it). The right to keep privat kapital/property and right to trade freely is core of capitalism in opposite to planned economies where people can not trade, only state trades and is owner of companies. The conditions of trade are most probably decisive how the capitalism is perceived if allowes riba, unfair practices, or it is more social oriented etc. Anyway I dont know how loan system functions in islamic banks - would be intersting to know w salam