Specialization is one of the most important motors of economic development. Not every community can or should try to produce everything.
Thankfully computers exist now so it is really not onerous at all to charge the correct duties and massive fees if you want to make the customs people do work (this is basically now the EU approach, and AliExpress had no problem adjusting).
I’m fairly certain Amazon knew these consumers weren’t paying use tax instead. Local stores took a beating by having to play by rules that Amazon didn’t.
By starting with books (and then CDs/DVDs), Jeff picked a good target: inventory that doesn't depreciate too fast, subsidized shipping, not needing to collect sales taxes up-front, high costs at b&m level, high value per weight/volume, popularity of carrying large inventory (books aren't too fungible)
Much better than pets.com selling cat and dog food.
Seriously people, we have computers now. Every SaaS in Europe needs to pay correct VAT on every subscription sold based on the customer origin, it is not at all unreasonable to have online sellers pay duties for products shipped to US.