Financially motivated to not prioritize security.
It's hard to sell what your product specifically can't do, while your competitors are spending their time building out what they can do. Beloved products can make a whole lot of serious mistakes before the public will actually turn on them.
"Our bridges don't collapse" is a selling point for an engineering firm, on something that their products don't do.
We need to stop calling ourselves engineers when we act like garage tinkerers.
Or, we need to actually regulate software that can have devastating failure modes such as "emptying your bank account" so that companies selling software to the public (directly or indirectly) cannot externalize the costs of their software architecture decisions.
Simply prohibiting disclaimer of liability in commercial software licenses might be enough.
Call yourself whatever you choose, but the garage tinkerers will always move faster and discover new markets before the Very Serious Engineers have completed the third review of the comprehensive threat model with all stakeholders.
Yes, they will move fast and they will brake things, and some of those breakages will have catastrophic consequences, and then they can go "whoopsy daisy", face no consequences, and try the same thing again. Very normal, extremely sane way to structure society
The only reason this works out the way it does is because certain governments have been corrupted by business interests to the point that businesses don't have to face any accountability for the harm that they cause.
If companies were fined serious amounts of money and the people responsible went to prison if they committed gross negligence and harmed millions of people, the attitude would quickly change. But as things stand, the system optimizes for carelessness, indifference towards harm, and sociopathy.
Nobody cares about bridges collapsing if you built the first bridges and none have collapsed yet from the couple first folks trying them out, though.
It's only when someone tries to drive their loaded ox-driven cart through for the first time that you might find out what the max load of your bridge is.