If your industry is run by unethical people who would use your code, if developed in the open, in a way that would put your firm out of business and create orders-of-magnitude-fewer jobs than your firm would IF it kept that code proprietary and used it as a way to leapfrog the status quo... then I think you have a very good argument for your company keeping its core code under wraps.
And even once you're at the scale where you can compete head-to-head with those people, you still might want to keep things proprietary so that you can encourage ethical and aligned behavior across the industry. Because the stakes are much higher than falling asleep happy because you maintained the "purity" of the open-source-software movement.
You'd still share your changes to zlib and other non-core components, though. Because of articles exactly like this. But none of the secret sauce.
As a side note, it is not at all my intent to imply that any of this refers to the finance industry. Not at all. Nope. (But if this piques your interest, send me a message at the email in my profile.)
And even once you're at the scale where you can compete head-to-head with those people, you still might want to keep things proprietary so that you can encourage ethical and aligned behavior across the industry. Because the stakes are much higher than falling asleep happy because you maintained the "purity" of the open-source-software movement.
You'd still share your changes to zlib and other non-core components, though. Because of articles exactly like this. But none of the secret sauce.
As a side note, it is not at all my intent to imply that any of this refers to the finance industry. Not at all. Nope. (But if this piques your interest, send me a message at the email in my profile.)