I think some of that's the difference between high school and college. Even today's more even-tempered history and civics classes in high school really downplay problems in our history and our systems, overall, including problems with the media, but as soon as you hit your first serious media studies textbook or course or just slip into a subculture that's into that sort of thing so assumes some familiarity with it as a background (politics nerds, certain flavors of history buffs, basically any leftist movement) you get a rather different idea of how things are going, and have gone, and realize that contemporary media criticism is part of a long tradition that's advanced similar complaints and made similar observations about structural problems with the media (access-related conflict of interest, slant via selection of what's "newsworthy", bias toward reporting violence or the otherwise shocking, ownership- or advertiser-related conflict of interest, susceptibility to lazily repeating propaganda from official sources, et c.) for pretty much the entire time this has been a field of study.

High school history class might cover e.g. yellow journalism as some temporary historical phenomenon, but won't usually dig into, say, the fact that the idea of "unbiased reporting" or "just presenting the facts" or "we report, you decide" are all kinda questionable to begin with—which facts? Which stories? When and how ought media provide context for a story, or leave it out? I can lie with facts all day long, it's not even hard. Half the lies on the actually-kinda-news segments of Fox News (yeah, sorry, still picking on them because they're an easy target) are just them reporting things without the context that makes it plainly a non-story—they're "just" reporting the facts, but it's slanted as hell, and they're deliberately implying things that aren't true by leaving out the context you need to tell that they're wrong. Take it another direction, and you can lie by providing the wrong context (not a lie in the sense of an outright falsehood! Just selective presentation). The history of media as largely explicitly partisan for much of the country's history will likely also barely be covered, and will almost certainly not be connected to the current state of media.

... but not everyone ends up seeing that expanded view. Maybe what I'm not accounting for is a recent popularization of a kind of shitty, partial, divorced-from-scholarship-and-history version of that POV, through the mechanisms and circumstances you mention, the holding of which might convince someone that this is a recent development, for lack of the rest of that context. "Now the media lies sometimes! That's new!"

I don't think the media landscape's wholly unchanging, and do thing some things like the loss of the fairness doctrine and our allowing some pretty incredible levels of media ownership consolidation has had some ill effects (though the death of the fairness doctrine would have little effect on the Internet, anyway, and the main outcome of losing it was the rise of partisan commentary and opinion without balancing counter-point, not more-slanted news—basically, it allowed the current much-maligned "media bubble" effect to get a running start way back in the 1980s, well before the rise of the Web as something normal people used, but that was mostly accomplished through commentary shows, not reporting). I'm just skeptical that we were ever a ton better off in terms of, specifically, news media honesty and integrity than we are now.

> I had a one-semester Current World Affairs class in high school in 2007, and we spent most of it watching cable news, reading newspapers, and talking about it, without any of the default critical position you'd (hopefully??) expect today.

Schools have to be damned careful how they treat current events. Parents get pissed off in a hurry over some really, really dumb shit, like "acknowledging basic things about reality that definitely shouldn't be controversial" sorts of shit, and if there's one thing schools hate dealing with, it's pissed-off parents. Start analyzing slant in media reporting in high school, as a teacher, and you're courting a reprimand even if you do your job perfectly and entirely objectively (somehow). "The closest thing to a widely-agreed-upon-to-be-neutral source we can find, presented with minimal commentary" is often the best they can realistically manage, and even that will get angry phone calls from time to time.