No, it would make IT security about as expensive as good lawyers. Just to cover the losses. A method to reliably produce vulnerability-free software is not invented yet.
That's not the goal. Well it is, but it's unachievable. We need to get people to care about security beyond ensuring that teenagers can't trivially get in—the current state of affairs for enterprise IT.
A law would at least require companies to give a fuck beyond the "can the CEO's niece break in" level.
I beg to differ. We have formal methods, ranging from type systems to full blown verification. This isn't a technical problem, it's an economic one.