If jury nullification doesn’t exist, then juries are pointless
That's just not true, though. I say that without taking a position on the merits of jury nullification. Juries are generally charged with determining matters of fact; the judge matters of law. Even without jury nullification, a jury still determines whether the person performed a proscribed act, or did so with the requisite intent, etc. When people talk about jury nullification, they generally mean the act of a jury…
I've always found this deeply troubling. If the law isn't clear enough for 12 jurors to determine if an act was legal, then how is it possibly just to hold the accused liable transgressing it?
I don't see much practical difference between this and ex-post facto laws. In both cases, a person can be convicted for an act that wasn't obviously illegal at the time.