> Or their firm would tank, because companies that don't put profit first can't survive on the market.
I would argue that this is not strictly speaking true. There are successful companies which don't (seemingly) put profit first. Examples include Morning Star (tomatoes, not the newspaper)[1], Mondragon[2] and perhaps most co-operatives in general.
One aspect that is often overlooked is that it is necessary to balance the books. This is an universal requirement when resources aren't unlimited and it applies to physics, biology, and economics.
Capitalism very clearly and unapologetically forces this, while some people imagine that, somehow, that constraint does not apply in other systems.
I would argue that this is not strictly speaking true. There are successful companies which don't (seemingly) put profit first. Examples include Morning Star (tomatoes, not the newspaper)[1], Mondragon[2] and perhaps most co-operatives in general.
[1] http://www.morningstarco.com/
[2] https://www.mondragon-corporation.com/en/