Not-for-profit (including that as part of the qualification of a tax exempt nonprofit) has nothing to do with the entity not making surplus revenues, it has more to do with the entity not being a tool to return profits to those who control it.
"Investment" is often used in senses where the return being sought is a social good and not a financial return to the investors. This could be viewed as either a metaphor for financial investment or a literal investment in utilitarian terms for which financial terms are, after all, only a convenient proxy.
