An excellent point. I've always assumed that most people don't want to expend dollars and lives on wars but that doesn't necessarily hold true.
Personally I'm more interested in the nugget of insight than necessarily the exact methods he outlines.
For all the million little ways that the government involves itself in our daily lives there is huge asymmetry and thus plenty of opportunity for injustice.
For the really big things there is also huge asymmetry. If something is a really big deal and even 10% of the US population went to Washington to protest you'd probably see a swift reaction. That's a really good thing and it's one of the reasons that many systems of representative government do work.
The question in my mind is: What is the price for big freedoms in terms of little freedoms, and is this a good bargain? Personally I'd like to have my big freedoms AND my little ones too. So any kind of thought along those lines is interesting even if it's not ultimately good.
The thing I took away from the article most is that there probably are ways to give the people more freedom on the little things without necessarily compromising on the big ones. Not necessarily via Assassination Markets, but SOMEHOW.