That seems to be the case for US media... here in Germany, it's a bit different at least for quality media. Spiegel, Heise, Die ZEIT and T-Online all happily link to sources, even up to competing news media.
thesmokinggun.com already does provide a fine repository of current and past court filings of interest. They've been around for years, and some journalists do link to them. Intriguingly, the one ad on their site at the moment is for diamond engagement rings.
I suppose that ad's positioning could be just random programmatic placement. But if anyone in the HN community can figure out why court-filing enthusiasts are especially likely to want to buy an engagement ring off an unverified website, I'd love to know more
It seems that rule number one of running a news site is to never have any external links. It's like a casino, they want you to come in and get lost.