1. So the problem of calculating and distributing use tax is complex... That sounds like a business opportunity for a new kind of web service.
2. I think the issue just comes down to online retailers dragging their feet because they want to enjoy their advantage as long as possible.
I wish it were that simple. This bill would have effectively shut down my small business (we're an online retailer). The overhead of paying taxes across many different states and municipalities is, frankly, impossible for smaller teams / startups to deal with. Even if we could outsource this, it would effectively reduce our margins to the point where we couldn't compete with brick & mortar. We already collect taxes and pay them to the states we operate in. This bill wouldn't cause us to pay more tax (we're based in California, so we'd probably pay less taxes as a result), but instead seems like it's more a result of anti-competitive lobbying efforts from B&M retailers.
2. Of course, Amazon.com got CA to agree waiting before taxing bc they knew once people tried prime, they would be hooked and would pay the tax later since there will be no alternative.