Generations?! Nah. When we Americans had 3 or 4 TV stations, it was a far different media landscape. Each was terrified of seeming biased, strove for neutrality. The driving factor for tuning into a given broadcast was trust in the news anchor. Not trust as in, "I agree.", trust as in, "I believe he's telling the truth and won't get called bullshitting." And they all basically reported the same news. Say what you will of that, but we were on the same page and neither the government nor the rich had much of a say.

Journalists used to hunt politicians for sport. Check the comic Bloom County for what it was like in the 80s. After Watergate, it was "weapons free" on politicians, the more dirt, the better. But there better be meat on that bone! PROOF.

It was funny and sad seeing Al Jazeera America try to take hold. Their mission statement was utterly unbiased reporting. And it was. And it was dry as paste. I have some journalism education, the American version was as unbiased as anything I've seen from American news since the 80s. After decades of "infotainment", I'm ashamed to say it was hard to read. They lasted one year.

tl;dr: News bias is a relatively new thing.