They acknowledge but do not even address the "cops breaking down your door" problem. I don't think it admits of a solution. Technical approaches like putting unknown MACs behind a firewall to block filesharing or filter the web are imperfect and prove that you knew leaving your wifi open might help baby-rapers.
(Pardon the throwaway, but I do run an open wifi. If I do win that unlucky lottery, I don't want some zealous prosecutor digging up this comment.)
In a world where it was understood that everyone ran free wifi, the courts would stop accepting that illegal activity from your IP was a reason for the cops to break down your door. Just as it's obvious today that illegal activity from a Starbucks open wifi isn't a reason for the cops to break into Starbucks.
I'm not saying it's easy to get there from here, but a solution is clearly not inherently impossible.
(Pardon the throwaway, but I do run an open wifi. If I do win that unlucky lottery, I don't want some zealous prosecutor digging up this comment.)