1. "I want good journalism but can't find it."
2. "The general public is being fed a diet of bad journalism."
To someone who's making complaint 1, it's very reasonable to reply "It's out there, you're just looking in the wrong places" (assuming that's true, which seems plausible).
To someone who's making complaint 2 -- which is how I read Tim Bray here -- that doesn't seem like such a helpful response. Telling Tim to look for better news won't do anything to raise the overall level of journalism.
(Of course a good response to complaint 2 may be "This is an insoluble problem; people will watch and read what they want to watch and read, and it turns out they don't want what you consider good journalism".)