I'd wager the vast majority of folks on the internet don't even know what a participatory mailing list is. And I say that as someone who has been a part of multiple lists for nearly 20 years.
I'm on ten or twelve different mailing lists. Only two have anything whatsoever to do with tech. The rest are - as per dfc above - politics-related.
So I don't view lists as somehow a techie habit - quite the opposite, in fact. They work for politics because the technical 'barrier to entry' is very low. You don't need to know anything more about computers than how to send and receive email in a client of your choice. Given that in most political groups you're dealing with students, pensioners and everyone in between, this is a distinct evolutionary advantage.
I have no idea how the total volume of list-mail breaks down between tech stuff and muggle concerns. But in any situation where you have to communicate between people of different generations with wildly different technical expertise, lists are an ideal lowest-common-denominator.
Until, that is, Yahoo or whoever cut their users off, and muggins here has to explain to uncomprehending people why their messages aren't appearing.
With just my eldest, 10-yo daughter, I have subscribed to 9 mailing lists at 3 different schools in two countries, to discuss things with various groups of parents, with none of these lists being started by tech folk.
