Just to play devil's advocate, "Police have said that most of the confiscated firearms had been stolen or found in abandoned homes..."
Obviously this may or may not be true, but if it is, how many actually support the return of stolen guns to the people who stole them?
Moreover, a return program was already in place; it just required that you prove ownership. This proved understandably difficult for folks who had lost everything in the flooding, but by the same token, you can't just give a gun to every fellow who walks in saying "Um, yeah, it was a Glock. Black. 9mm. Yup, that one looks like it!"