For a long time in the past, there was the belief that Americans wouldn't understand British shows or even British accents. David Attenborough refers to that in his book "Life on Air". The BBC wanted to sell his first big series to the States, but the networks they approached wouldn't buy it if they couldn't dub DA's voice with an American actor. Fortuitously, there was a clause in DA's contract that his permission was needed to sell that series; and he refused. Subsequently, the series was sold to PBS, albeit at a much lower price, but with DA's voice.
By the time of his second big series, the same issues arose; but by that time, DA's reputation was good in the USA, and the sales of his DVDs there were huge. The networks backed down and paid a proper price for broadcasting his series with his voice.
I found that story quite hilarious. After all, the USA is geographically huge, and probably has a greater variety of accents than any other country. So why would TV network executives think that audiences couldn't cope with a global nature programme being presented by a Brit?
I always think twice now when people say that TV is being dumbed down - the question being: by whom? I don't think it's the audience.