Or not. Who knows. The point is, this 'economically it is more efficient' is not a proven case because the externalities need to be taken into account, and so far the person I've been responding to seems to not understand this part, or is ignoring it.
The tradeoff may be worth it in some contexts, but if you don't understand that there are tradeoffs, you're going end up proposing silly policies like the original commenter's idea that nobody should ever be allowed to destroy any object a consumer could use.
If the benefit they get from waste is like 10% of the value they're destroying, then in a broad sense it is pointless.
And nobody is arguing against oversupply. Oversupply itself is fine.
Clothing is of course a bit easier to deal with (it'll still grow mildew if you don't protect it from moisture!), but the source link explicitly anticipates there will be some circumstances where it's impossible to give away clothing and authorizes destruction in that case.
This isn't some random guy. Their entire job is dealing with the logistics of big piles of clothes, and they have months in advance to plan.