When a government abdicates its duty to protect its citizens' natural rights, it forfeits their obedience. Had I been on Goetz' jury, I would have refused to convict him. Congress can grandstand and pass whatever it wants, no matter how unreasonable or irrational. This doesn't mean that jurors have to enforce the legislation. Few believe that violent crime, theft, and so on are acceptable.
Jury nullification can, in fact, prevent criminals from escaping justice.
I recall that one of the LA rioters who beat Reginald Denny escaped conviction because of the judge's faulty instructions. The judge told the jury that the only available verdict was attempted murder. I recall that the prosecution had a videotape of the defendant beating Denny with a brick, but it couldn't prove that he intended to kill Denny. The judge's instructions, therefore, forced the jury to acquit the defendant. The next judge might have included aggravated assault in the next jury's options.