Debt was disallowed mostly for religious reasons in that time period, likely rooted by the challenge posed by paying off deflationary debt. During the Renaissance and subsequently the period of most colonialist expeditions debt and investments became more commonplace. Of course in a world that experiences deflation you will be more wary of how you gamble as doing nothing can be good enough but as along as there are asymmetric bets people will invest, take debt, and gamble all expecting higher returns.