It was dumbed down in the sense that it kept switching between three or four different stories, pretending that they were happening simultaneously ("Meanwhile, two stations west at Bond Street..."), and every time they switched story they had to remind us what was going on as if it were a week rather than ten minutes since we saw it. I don't know whether today's documentary makers have lost the art of putting together a grown-up programme or whether they are simply pandering to the diminished attention span of today's youngsters (who are probably also tweeting and updating their Facebook status while half-watching the programme).
I doubt those with 'Facebook status/es' would know what Crossrail is, let alone where it's being built.
As I said in my post which you conveniently forgot to quote, a generic program is far more likely to generate greater interest than a more esoteric one, even if you feel that's so below you it's not worthy of any channel other than cBeebies. :roll: