The kids who watched Magpie were probably only watching it because they fancied the presenters.
Let's be serious, though. I come from a family of factory workers and grew up on a council estate. I was allowed to watch any channel I liked for kids' TV (and it often was BBC - Jackanory, Blue Peter, Grange Hill etc.), but as soon as that was finished, it was ITV news and ITV for the rest of the evening. The ITV news and that regional programme they always do around teatime was considered 'more our sort of news' even though we got West Midlands news and we lived in the East Midlands, so it still wasn't relevant.
My parents always thought BBC was a bit too intellectual for them, I think (indeed, Mum says as much even now). We certainly never watched BBC2 - that was telly academia to them and not for the likes of us at all. I pretty much adopted their viewing habits into my adulthood.
These days, however, I hardly ever watch ITV. It's mainly one of the BBC channels, Channel 4 or comedy repeats on UKTV or Dave. Maybe this reflects my intellectual growth, as I left school at sixteen with zero o'levels and spent several years doing menial work in factories and supermarkets before starting to educate myself, going to university and getting a degree.