@Hogger85b the article mentions why:
This means the money needed to pay for the product and ship it out is not received until after it is made and shipped.
A lot of sellers don't want to force their customers to pay for tracked shipping because international tracking can rack up a huge cost.
@skates
The article also goes on to show the typical Etsy customer and seller mentality (and as an Etsy customer I can say I also share this mentality. Keep in mind that most of the things sold on Etsy are small artisan/crafted goods and a lot of times the shipping cost can cost more than the item itself, much less tracked shipping):