what does "work" mean?

that it maximises profits for HN posters?

that it maximises some abstract goodness for society?

that it provides good quality products at the lowest prices?

the fact businesses keep doing something doesn't provide any information on if that's good for anyone else.

Profit in software companies does in fact provide most of those example.

Only the last one needs some clarification. If a business did not do things that benefit others, they wouldn't get paid. So, almost by definition, businesses do. You might argue that a bigger value could be provided in another way, but it definitely does provide value.