Part of the reason for this constant repetition is the way north Americans - in particular - watch TV. There is very little "appointment viewing". What I mean by this is that people don't tend to know in advance what they're going to watch: they haven't read the listings beforehand.
Instead, they sit at their screen with a remote and begin to click, until they find something interesting; something that attracts attention. Viewers may have as many as 500 channels to choose from. (I think substantial amounts of money are paid to place channels near the beginning of this list: numbers 1 or 3 are likely to get more clicks than 397.)
Broadcasters need viewers to know what a programme is about within a short time of "clicking onto" it, and they want the viewer to stay with the programme as long as possible. (Remember, the broadcaster makes money by selling a certain number of "eyeballs" - eyeballs of a certain demographic, such as "men between 25 and 45" - to advertisers.)
(Incidentally, I think I remember hearing that a typical "loyal" viewer might stay with one of the larger factual cable channels for an average of as little as 10 minutes a night.)
This is why programmes constantly repeat information: so that, no matter when you start watching, you know what the programme is about. And you're given a reason to keep watching and stay tuned - particularly over the next commercial break.
To those whose habit is to watch an hour-long programme from beginning to end, the repetition can be frustrating. But that sort of programme doesn't work for commercial broadcasters, for the most part.
I like "old style" documentaries, too. We may need to look for them elsewhere in future.
I don't see the relative dearth of them on TV as anyone's fault, and I don't think there's a conspiracy to manipulate us; I see it rather as an inevitable result of what people are prepared to pay for, and give time to.
I think there is truth in the idea that people will watch whatever's made available to them, but the experience of commercial television shows that, when choices are available, documentaries aren't a preferred viewing option - particularly "old style" documentaries.
I think this is because, as I mentioned in a previous post, most people are using their TVs for relaxation, rather than stimulation/education.
I don't think this means that people don't want to be educated and informed; it's just that they don't seek this from much of their television-viewing.
@DeepRed et al: my point was to address the questions in the original post.
I think commercial broadcasters have found that traditional documentaries aren't working for their business. I've observed that those who have attempted to build a broadcasting business based on them have tended to fail, or survive by moving to more populist fare.
Those who want to see or make traditional documentaries might need to look elsewhere for funding and delivery/transmission.
Regarding "quality" television and "crap" TV: this is clearly an area where individuals' values differ, but my understanding from interactions with people who are involved in the business is that most people use television to "blob out". Another way of putting this is that most people are using TV for entertainment, rather than for education or enlightenment.
Many programmes are purchased from the US, where I know "Pawn Stars" had a significant effect on the character of "factual" or "unscripted" programming because it rated very highly - and still does.
A commercial television company is bound to show programmes that deliver most "eyeballs" to its advertisers. The penalty for failure is severe, which discourages risk-taking. Consequently, the broadcasters tend to be conservative in their approach to innovation: it's very common to find "clones" of a successful series on competing channels.
I've observed that television channels that start out as relatively "high culture" tend to move "down market", since this seems to make more money - partly because audiences increase, and partly because programmes for this market can be made more cheaply (though not necessarily).
There are certainly differences between the US and Europe, for example, where I think governments play a greater role in regulating and financing television.
Television in New Zealand is essentially all commercial and - from my perspective - its programmes reflect this. What's offered may not be to your taste but it seems to be working for the businesses concerned.
(Removed: someone else already answered the question.)
Bob Marley duetting with Elvis?
You've unlocked the box, Russell...
I used to make these!
Found a small extract:
The complete version lasts about an hour.
I suppose I like to think of myself as eclectic in my tastes. (Maybe everyone says that.) This piece, however, is pretty hard work. I challenge you to listen to it all the way through.
I think it's how we learn to sing. We hear American accents (which have long been prominent in popular music) and, consciously or otherwise, copy them. It's no longer "American", necessarily; simply part of the genre. I remember a series about popular music on TV years ago, in which one interviewee traced a lot of it back to the Appalachian influence in Country music which, itself, had a strong influence on early Rock and Roll.
I can remember singing teachers (and others) of the 60s and 70s being really disparaging about American accents. (Actually, I remember some people being pretty negative about the Kiwi accent(s) in singing. The word "the", for example, pronounced in a NZ accent, was anathema to one choir conductor. I think that was partly because of what it tended to do to the length of the sung note.)
A similar thing used to happen in theatre with English accents.
One of the best ways to learn is by imitation. In the early stages, we don't know which parts of what we're imitating are going to be most important to us. As we become more confident and experienced, we find our own "voice" (see "mojo" above).
If market forces are important to us, then we might tend to stay with an "American" pronunciation. It does seem to be easy to sell to the "world market" by comparison to other accents.