"But experts say the problem isn’t with lack of discernment on the part of site publishers but with an extremely complex online advertising system that makes it hard for publishers involved to detect, let alone weed out, misleading and malware-laden ads."
Which is crap. It's your site, you're responsible for what you run on it. If I ran a store, and the guy from the company that cleans the floors occasionally stabs customers in the face, nobody would accept me shrugging and saying "well, it's really hard to tell which companies employ face-stabbers so I guess you're just going to get some face-stabbing every once in a while. Sorry".
If you go to a site and you get malware from an ad network, it's because the site owner doesn't care if you get malware from an ad network. Full stop.