Whether Levitt has thought about it for 10 minutes or 10 lifetimes may explain why he is a pessimist, but not whether his conjecture is correct. It is also worth pointing out gun buyback programs exist in the context of the regulatory regimes of a given jurisdiction, so the failings of previous programs are irrelevant when considering their implementation in the context of different regulations.
Backing up to considerations about empathy, it is somewhat ironic and wishful to think a federal government that lacks the requisite empathy to institute basic, commonsense gun reform could be relied on to promote empathy. This is doubly true when the previously-mentioned hijacking of the federal government by special interests to the point that the democratic will of the people is continually rejected actually relies on sowing fear and divisiveness to survive.
Nothing like the Aarhus program that was discussed is feasible under such a regime. Aarhus exists in a more socialistic nation with less political corruption and less wealth inequality.
In other words, the same type of government that could bring us meaningful gun reform could also engender a higher level of aggregate empathy and vice versa. It’s kind of a Catch-22 to argue one over the other.