I think the point is predicated on a situation where the candy is important ("favourite candy"). Substitute for anything else precious to the child. Intentionally destroying something precious, even a small thing, is indicative of something nasty. It serves only to build disconnection.

I don't read it as destruction. Kids should never be entitled to sweets, so the candy is not in any way theirs. And I don't think that they should receive sweets as a reward for being decent human beings.

Sweets are extra. A sign of affection. A toast to achievement.

I imagine a captain pouring a bottle to the sea every time someone gets to a fight an ship crossing the ocean.

(I say this as someone who doesn't give their child sweets!)

IMHO if a child is behaving in a way that you don't like, it's your job, not theirs, to close that gap. Are you putting them in an overwhelming position, asking too much of them, emotionally distancing yourself? Do they have the mental capacity at that age to balance behaviour regulation with delayed gratification? (e.g. a long drive they can't cope with, the promise of sweets if you're "good")

If you're bribing good behaviour with the promise of something, and you have that thing in hand, throwing it away just seems mean. That's different to not giving it to them. It's an irretrievable act, and shuts down any continued negotiation.

Stigmatising natural behaviour, and then washing your hands of the situation (because you can't get that sweet back) doesn't sit right with me.

It is to a 4 year old.

I think this is a case where it varies hugely. For some kids I’m some families sweets are a huge deal and can be a contentious issue, to others they’re really not a big deal.