As the parent comment said, I'd like to see the NSA working to get zero day vulnerabilities fixed as opposed to hoarding them for future exploitation. At least this is my perception, to be honest aside from a few examples I've heard of I don't actually know whether I've correctly characterized their activities, they may already be doing this.
I agree to a point, but to continue the physical-security analogy: while private businesses should not be negligent in securing their property, a patrolling police force should also exist to discourage theft and vandalism at large.
I think the private and public sector have both been negligent when it comes to cybersecurity. Both need to improve. (Like you, I'm willing to bet the private sector is hoping to sit back and let the taxpayer foot the bill for everything. This is a problem too.)
We should regulate and punish, not subsidize. The same way we have dealth with corporate recklessness for decades.