In any case, BP was never the cool show to watch as a child. It was seen as the middle class kids show parents expected you to watch, even though I enjoyed elements of the programme.
I'm not sure my parents ever " expected " me to watch Blue Peter but at the time it was there and if it was interesting enough then I'd watch. There was certainly a time just before they left TVC and moved to Salford where it had seem to have lost its way and could have been replaced by any magazine format. Why stop showing it if it's still watched ? It's never going to go back to getting the viewers it did in the 70s / 80s now that we're in a multichannel world. But if it's still working, why get rid of it ? It might never be " trendy " whatever decade you watch it in, but if you watch it now it has moved with the times and is very less stuffy without the presenters trying too hard... Unlike many programmes for young people.
Besides, there are plenty of equivalents of Blue Peter in other countries - RTE's Echo Island was virtually identical.
I think there is some truth to the argument that Blue Peter has an image of being a programme for staid and slightly geeky middle class suburbanites. I doubt that it was ever intended as the coolest or the trendiest of children's programmes from the outset but it was big back in the 1980s and 90s - like Newsround also was. The problem these programmes have faced in recent years is the fragmentation of how kid's get their video fix in after school hours. A significant difference between Blue Peter and Newsround is that Blue Peter is a reasonably easy programme for any producer to clone whereas a Newsround clone will be difficult for any producer without a news gathering infrastructure.
There definitely have been programmes similar to Blue Peter in other countries over the decades. It might not be a format appealing to the American audience but it has been tried out in 'third world' countries due to its relatively low cost of production.