As I understand it, it's hard to monetize shady websites using anything except shady things like adware. Look at 4chan and it's perpetual struggle to get advertisers.
the docket mentions that - it's 260M sessions/visits p.a but only ~10% are from the USA with most traffic from emerging markets, so not really monetizable[0]
pay-per-download malware, otoh, can pay $5+ a hit even in those markets
the court filings don't mention malware but it might be a much more effective way to have the domains seized
[0] also indicative of this is the ad networks used - propellerads, pushwhy, addthis, yandex - the first two are blocked almost everywhere because of malware distribution
