This is the standard/traditional theory of business, right? No one person decided it, it's just a theory about a capitalist markets. This theory is cited as one

This is the standard/traditional theory of business, right? No one person decided it, it's just a theory about a capitalist markets. This theory is cited as one of the main guiding principles in corporate ethics as well. https://www.accountingtools.com/articles/2019/1/25/shareholder-theory https://www.accountingtools.com/articles/2019/1/25/sharehold...