First of all, even ignoring society, the question of ‘first order goal’ can get murky even within one organization. The ‘business’ that the developer is creating a product for may be offering a service to another group within the firm, and that service may have very little to do with the actual ‘end goal’ business of the firm. E.g. a software group may be developing an application for the accounting group of a toy company. How much a software developer really needs to know about toys in this instance is questionable (but they do need to know something about accounting needs.)

Even in the context of working for a trading desk there’s a difference between understanding / appreciating the mechanics of trading (which is necessary for a good developer to know working on such a team), and the strategy behind the particular trade being made (which may be less necessary.)

There’s a ‘turtles all the way down’ (or up) aspect to this, which leads into your point about the value trading has on society. Making this far more general for a moment I think this is more a question of ethics / morality on the part of an individual, rather than whether they are a good developer or not (and my entry was a discussion on the latter.) Say the accounting team above was actually working for a cigarette manufacturing firm. If I was writing software at such a firm I wouldn’t need to know much about cigarette manufacturing to do an excellent job for the accounting team, but I would have a personal choice as to whether I wanted to contribute to the business overall.

DRW would argue it provides value to the market (world) through ‘liquidity provision’. I’d be happy to discuss my opinion over a beer since it’s somewhat complicated but ethics about the company’s general objectives were not a primary reason for my leaving.