Source address validation, or more generally anti-spoofing filters, do not require providers maintain logs, perform content inspection or install firewalls. But source address validation won't stop attacks, viruses, child porn, terrorists, gambling, music sharing or any other evil that exists in the world. So the proposal "1" gets extended to include other stuff. It gives better ROI when more than SAV is included.

i can see how this could happen. however, i do not think that it is the reason why SAV is not gettign deployed.