Generally speaking, I agree 100% that it makes sense for both the seller and the buyer to split the loss.
On the other hand,
argument no. 1: don't we all use a standard disclaimer in M2M sales that it is the buyer who takes all the risk and the moment when the package leaves the seller's hands it is on the buyer? If the buyer doesn't like such condition, then does not have to buy.
Argument no. 2: there is a no profiteering rule, that's why M2M watches are cheaper than TD, often by more than 30-40 usd (shipping costs from TDs!). If I recall correctly from economics 101; higher risk=bigger gain; lower risk=higher price. So in other words, you are paying less for a watch, which often is already within the EU (or CONUS), so the custom risk is lower; but on the other hand, if something happens with the parcel, you are screwed. One can always buy from a TD, pay more, but be safe that if anything goes bad, then the TD will figure it out.
And this comes from someone, who stopped buying from TDs and now uses M2M only