Dont agree with that last statement. The idea that the seller can be solely responsible for it arriving and in full working order is not reasonable. The seller and the buyer both accept a risk in agreeing to sell and buy. As long as the seller has done all thats reasonable and given disclosure of the item then any event that might take place during its journey is not the sellers sole responsibility, it cant be. Otherwise the seller is equally if not probably more open to scamming than the buyer is.
Admittedly most defects identified upon reciept can be usually identified as a defect in transit or prior to shipping, yes there are grey areas but on the whole it can be identified. Any problems should be discussed between both people and a reasonable agreement reached, if it cant be then the mods can help in bringing the issue to a satisfactory conclusion for both guys. Most of the time we can do that ourselves in the spirit of this forum. In turn you then have the risk of the buyer saying it hasnt arrived especially if you have sent the watch by a method that cant prove it but if you have done so then it could still be a case of 'well I didnt receive it'!
But I dont think its right to accept responsibility as a seller for the watch arriving in full working order or indeed arriving at all, as long as, as I have said the seller has fulfilled or honored his description of the item and packaged and sent it in the most reasonable way or as agreed/requested. I think there is a balance to this not a sole responsibility.
I do however agree with the sentiment just not the practicality of it.