The Bob Woodwards of the world don't come out of a vacuum. They're part of a larger system in which digging into a problem takes time, and many don't succeed. That means you need a lot of people trying to do it. That means you need some system that is paying for and encouraging people to do this, you can't rely on a couple of independently funded bloggers to carry the load for everyone.
Given your "most of it pablum" talk above, I can guess you don't know anyone who works in a good newspaper or a local television station's investigative unit. I agree 24 hour news networks are full of filler. Local news and the better newspaper's are a better representation of what "traditional journalism" looks like. They just have vastly reduced resources. But you get the people we're talking about here who dig into stories and find out what's going on. And when you talk to them, you hear about journalistic integrity. Yes really! I know it's fun to be cynical on HN, but journalistic integrity is a real thing that is alive and well but its funding is dwindling.
Secondarily, the idea that there is some sort of strong divide between "bloggers" and "journalists" is a fantasy. A journalist is someone who does journalism, period. It doesn't require a degree or special training, it requires doing it well. And there are many folks who have been doing it well despite being outside the realm of traditional journalism. It's insulting to call them "bloggers" or "amateurs" or whatever other nickname you can throw at them. To the degree that they do professional quality journalism, they are journalists.
Meanwhile, we labor under this idea that the established news media has been a particularly good example of journalistic quality. Largely this is because there weren't other examples to compare against. The reality is that the actual quantity of legitimate reporting, investigation, and worthwhile analysis in a newspaper or in a TV news broadcast has generally been incredibly tiny. A slim collection of pages, a handful of minutes. But we've gotten used to the patterns, the production values, the mythos, the sense of gravitas.
The reality is that most of it is pablum and the rest is thin gruel. CNN? An alien from another planet who just landed on Earth would look at the media and tell you to your face that there is a hair's breadth difference between CNN and buzzfeed, and not always necessarily in the favor of CNN. Most of the rest of the media is in the same shape, with only the tiniest handful of exclusions.
As you allude, preserving the traditional media isn't the right way to solve the problem, because they weren't solving it. Indeed, in some cases (FOX News, etc.) they have a tendency to make their viewers less informed and more ignorant. We shouldn't be asking ourselves how to get back to the glory days of the traditional media, that's largely a fantasy. We should be asking ourselves how people become informed in the digital age, and that's a much vaster topic than just the "news".